Java: Further style refinements

(detected by enabling additional checkstyle modules)

This commit also removes unnecessary uses of the "private" modifier in
the Java tests/examples.  The default access modifier disallows access
outside of the package, and none of these classes is in a package.  The
only reason we use "private" with member variables in these classes is
to make checkstyle happy, because we want it to enforce that behavior in
the TurboJPEG API code.

java/org/libjpegturbo/turbojpeg/TJTransformer.java

@@ -111,11 +111,11 @@ public class TJTransformer extends TJDecompressor {
    * which specifies the transform parameters and/or cropping region for the
    * corresponding transformed output image
    *
-   * @return an array of {@link TJDecompressor} instances, each of
-   * which has a transformed JPEG image associated with it.
-   *
    * @param flags the bitwise OR of one or more of
    * {@link TJ#FLAG_BOTTOMUP TJ.FLAG_*}
+   *
+   * @return an array of {@link TJDecompressor} instances, each of
+   * which has a transformed JPEG image associated with it.
    */
   public TJDecompressor[] transform(TJTransform[] transforms, int flags)
                                     throws TJException {