Add fault tolerance features to djpeg and jpegtran

- Enable progress reporting at run time using a new -report argument
  (cjpeg now supports that argument as well)
- Limit the allowable number of scans using a new -maxscans argument
- Treat warnings as fatal using a new -strict argument

This mainly demonstrates how to work around the two issues with the
JPEG standard described here:
https://libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf
since those and similar issues continue to be erroneously reported as
libjpeg-turbo bugs.

cdjpeg.h

@@ -4,7 +4,7 @@
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1994-1997, Thomas G. Lane.
  * libjpeg-turbo Modifications:
- * Copyright (C) 2017, D. R. Commander.
+ * Copyright (C) 2017, 2019, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -87,6 +87,9 @@ struct cdjpeg_progress_mgr {
   struct jpeg_progress_mgr pub; /* fields known to JPEG library */
   int completed_extra_passes;   /* extra passes completed */
   int total_extra_passes;       /* total extra */
+  JDIMENSION max_scans;         /* abort if the number of scans exceeds this
+                                   value and the value is non-zero */
+  boolean report;               /* whether or not to report progress */
   /* last printed percentage stored here to avoid multiple printouts */
   int percent_done;
 };