TurboJPEG: Numerous documentation improvements

- Wordsmithing, formatting, and grammar tweaks

- Various clarifications and corrections, including specifying whether
  a particular buffer or image is used as a source or destination

- Accommodate/mention features that were introduced since the API
  documentation was created.

- For clarity, use "packed-pixel" to describe uncompressed
  source/destination images that are not planar YUV.

- Use "row" rather than "line" to refer to a single horizontal group of
  pixels or component values, for consistency with the libjpeg API
  documentation.  (libjpeg also uses "scanline", which is a more archaic
  term.)

- Use "alignment" rather than "padding" to refer to the number of bytes
  by which a row's width is evenly divisible.  This consistifies the
  documention of the YUV functions and tjLoadImage().  ("Padding"
  typically refers to the number of bytes added to each row, which is
  not the same thing.)

- Remove all references to "the underlying codec."  Although the
  TurboJPEG API originated as a cross-platform wrapper for the Intel
  Integrated Performance Primitives, Sun mediaLib, QuickTime, and
  libjpeg, none of those TurboJPEG implementations has been maintained
  since 2009.  Nothing would prevent someone from implementing the
  TurboJPEG API without libjpeg-turbo, but such an implementation would
  not necessarily have an "underlying codec."  (It could be fully
  self-contained.)

- Use "destination image" rather than "output image", for consistency,
  or describe the type of image that will be output.

- Avoid the term "image buffer" and instead use "byte buffer" to
  refer to buffers that will hold JPEG images, or describe the type of
  image that will be contained in the buffer.  (The Java documentation
  doesn't use "byte buffer", because the buffer arrays literally have
  "byte" in front of them, and since Java doesn't have pointers, it is
  not possible for mere mortals to store any other type of data in those
  arrays.)

- C: Use "unified" to describe YUV images stored in a single buffer, for
  consistency with the Java documentation.

- Use "planar YUV" rather than "YUV planar".  Is is our convention to
  describe images using {component layout} {colorspace/pixel format}
  {image function}, e.g. "packed-pixel RGB source image" or "planar YUV
  destination image."

- C: Document the TurboJPEG API version in which a particular function
  or macro was introduced, and reorder the backward compatibility
  function stubs in turbojpeg.h alphabetically by API version.

- C: Use Markdown rather than HTML tags, where possible, in the Doxygen
  comments.

java/doc/org/libjpegturbo/turbojpeg/TJTransform.html

@@ -167,7 +167,7 @@ extends java.awt.Rectangle</pre>
 <tr class="altColor">
 <td class="colFirst"><code>int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#op">op</a></strong></code>
-<div class="block">Transform operation (one of <code>OP_*</code>)</div>
+<div class="block">Transform operation (one of <a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OP_NONE"><code>OP_*</code></a>)</div>
 </td>
 </tr>
 <tr class="rowColor">
@@ -223,7 +223,7 @@ extends java.awt.Rectangle</pre>
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OPT_COPYNONE">OPT_COPYNONE</a></strong></code>
 <div class="block">This option will prevent <a href="../../../org/libjpegturbo/turbojpeg/TJTransformer.html#transform(byte[][],%20org.libjpegturbo.turbojpeg.TJTransform[],%20int)"><code>TJTransformer.transform()</code></a> from copying any extra markers (including EXIF
- and ICC profile data) from the source image to the output image.</div>
+ and ICC profile data) from the source image to the destination image.</div>
 </td>
 </tr>
 <tr class="altColor">
@@ -235,8 +235,8 @@ extends java.awt.Rectangle</pre>
 <tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OPT_GRAY">OPT_GRAY</a></strong></code>
-<div class="block">This option will discard the color data in the input image and produce
- a grayscale output image.</div>
+<div class="block">This option will discard the color data in the source image and produce a
+ grayscale destination image.</div>
 </td>
 </tr>
 <tr class="altColor">
@@ -256,7 +256,7 @@ extends java.awt.Rectangle</pre>
 <tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OPT_PROGRESSIVE">OPT_PROGRESSIVE</a></strong></code>
-<div class="block">This option will enable progressive entropy coding in the output image
+<div class="block">This option will enable progressive entropy coding in the JPEG image
  generated by this particular transform.</div>
 </td>
 </tr>
@@ -270,7 +270,8 @@ extends java.awt.Rectangle</pre>
 <tr class="altColor">
 <td class="colFirst"><code>int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#options">options</a></strong></code>
-<div class="block">Transform options (bitwise OR of one or more of <code>OPT_*</code>)</div>
+<div class="block">Transform options (bitwise OR of one or more of
+ <a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OPT_PERFECT"><code>OPT_*</code></a>)</div>
 </td>
 </tr>
 </table>
@@ -509,7 +510,7 @@ extends java.awt.Rectangle</pre>
  the level of chrominance subsampling used.  If the image's width or height
  is not evenly divisible by the MCU block size (see <a href="../../../org/libjpegturbo/turbojpeg/TJ.html#getMCUWidth(int)"><code>TJ.getMCUWidth(int)</code></a>
  and <a href="../../../org/libjpegturbo/turbojpeg/TJ.html#getMCUHeight(int)"><code>TJ.getMCUHeight(int)</code></a>), then there will be partial MCU blocks on the
- right and/or bottom edges.   It is not possible to move these partial MCU
+ right and/or bottom edges.  It is not possible to move these partial MCU
  blocks to the top or left of the image, so any transform that would
  require that is "imperfect."  If this option is not specified, then any
  partial MCU blocks that cannot be transformed will be left in place, which
@@ -547,8 +548,8 @@ extends java.awt.Rectangle</pre>
 <li class="blockList">
 <h4>OPT_GRAY</h4>
 <pre>public static final&nbsp;int OPT_GRAY</pre>
-<div class="block">This option will discard the color data in the input image and produce
- a grayscale output image.</div>
+<div class="block">This option will discard the color data in the source image and produce a
+ grayscale destination image.</div>
 <dl><dt><span class="strong">See Also:</span></dt><dd><a href="../../../constant-values.html#org.libjpegturbo.turbojpeg.TJTransform.OPT_GRAY">Constant Field Values</a></dd></dl>
 </li>
 </ul>
@@ -573,7 +574,7 @@ extends java.awt.Rectangle</pre>
 <li class="blockList">
 <h4>OPT_PROGRESSIVE</h4>
 <pre>public static final&nbsp;int OPT_PROGRESSIVE</pre>
-<div class="block">This option will enable progressive entropy coding in the output image
+<div class="block">This option will enable progressive entropy coding in the JPEG image
  generated by this particular transform.  Progressive entropy coding will
  generally improve compression relative to baseline entropy coding (the
  default), but it will reduce compression and decompression performance
@@ -589,7 +590,7 @@ extends java.awt.Rectangle</pre>
 <h4>OPT_COPYNONE</h4>
 <pre>public static final&nbsp;int OPT_COPYNONE</pre>
 <div class="block">This option will prevent <a href="../../../org/libjpegturbo/turbojpeg/TJTransformer.html#transform(byte[][],%20org.libjpegturbo.turbojpeg.TJTransform[],%20int)"><code>TJTransformer.transform()</code></a> from copying any extra markers (including EXIF
- and ICC profile data) from the source image to the output image.</div>
+ and ICC profile data) from the source image to the destination image.</div>
 <dl><dt><span class="strong">See Also:</span></dt><dd><a href="../../../constant-values.html#org.libjpegturbo.turbojpeg.TJTransform.OPT_COPYNONE">Constant Field Values</a></dd></dl>
 </li>
 </ul>
@@ -600,7 +601,7 @@ extends java.awt.Rectangle</pre>
 <li class="blockList">
 <h4>op</h4>
 <pre>public&nbsp;int op</pre>
-<div class="block">Transform operation (one of <code>OP_*</code>)</div>
+<div class="block">Transform operation (one of <a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OP_NONE"><code>OP_*</code></a>)</div>
 </li>
 </ul>
 <a name="options">
@@ -610,7 +611,8 @@ extends java.awt.Rectangle</pre>
 <li class="blockList">
 <h4>options</h4>
 <pre>public&nbsp;int options</pre>
-<div class="block">Transform options (bitwise OR of one or more of <code>OPT_*</code>)</div>
+<div class="block">Transform options (bitwise OR of one or more of
+ <a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OPT_PERFECT"><code>OPT_*</code></a>)</div>
 </li>
 </ul>
 <a name="cf">
@@ -661,8 +663,8 @@ extends java.awt.Rectangle</pre>
  equivalent of setting it to (width of the source JPEG image -
  <code>x</code>).</dd><dd><code>h</code> - the height of the cropping region.  Setting this to 0 is the
  equivalent of setting it to (height of the source JPEG image -
- <code>y</code>).</dd><dd><code>op</code> - one of the transform operations (<code>OP_*</code>)</dd><dd><code>options</code> - the bitwise OR of one or more of the transform options
- (<code>OPT_*</code>)</dd><dd><code>cf</code> - an instance of an object that implements the <a href="../../../org/libjpegturbo/turbojpeg/TJCustomFilter.html" title="interface in org.libjpegturbo.turbojpeg"><code>TJCustomFilter</code></a> interface, or null if no custom filter is needed</dd></dl>
+ <code>y</code>).</dd><dd><code>op</code> - one of the transform operations (<a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OP_NONE"><code>OP_*</code></a>)</dd><dd><code>options</code> - the bitwise OR of one or more of the transform options
+ (<a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OPT_PERFECT"><code>OPT_*</code></a>)</dd><dd><code>cf</code> - an instance of an object that implements the <a href="../../../org/libjpegturbo/turbojpeg/TJCustomFilter.html" title="interface in org.libjpegturbo.turbojpeg"><code>TJCustomFilter</code></a> interface, or null if no custom filter is needed</dd></dl>
 </li>
 </ul>
 <a name="TJTransform(java.awt.Rectangle, int, int, org.libjpegturbo.turbojpeg.TJCustomFilter)">
@@ -678,8 +680,8 @@ extends java.awt.Rectangle</pre>
 <div class="block">Create a new lossless transform instance with the given parameters.</div>
 <dl><dt><span class="strong">Parameters:</span></dt><dd><code>r</code> - a <code>Rectangle</code> instance that specifies the cropping
  region.  See <a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#TJTransform(int,%20int,%20int,%20int,%20int,%20int,%20org.libjpegturbo.turbojpeg.TJCustomFilter)"><code>TJTransform(int, int, int, int, int, int, TJCustomFilter)</code></a> for more
- detail.</dd><dd><code>op</code> - one of the transform operations (<code>OP_*</code>)</dd><dd><code>options</code> - the bitwise OR of one or more of the transform options
- (<code>OPT_*</code>)</dd><dd><code>cf</code> - an instance of an object that implements the <a href="../../../org/libjpegturbo/turbojpeg/TJCustomFilter.html" title="interface in org.libjpegturbo.turbojpeg"><code>TJCustomFilter</code></a> interface, or null if no custom filter is needed</dd></dl>
+ detail.</dd><dd><code>op</code> - one of the transform operations (<a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OP_NONE"><code>OP_*</code></a>)</dd><dd><code>options</code> - the bitwise OR of one or more of the transform options
+ (<a href="../../../org/libjpegturbo/turbojpeg/TJTransform.html#OPT_PERFECT"><code>OPT_*</code></a>)</dd><dd><code>cf</code> - an instance of an object that implements the <a href="../../../org/libjpegturbo/turbojpeg/TJCustomFilter.html" title="interface in org.libjpegturbo.turbojpeg"><code>TJCustomFilter</code></a> interface, or null if no custom filter is needed</dd></dl>
 </li>
 </ul>
 </li>