Change log:

Version 1.7.0  (built with libpng-1.2.38 and zlib-1.2.3.2)
  Save (but do not recompress) APNG chunks if the output file has the
    ".apng" extension and the color_type and bit_depth are not changed.

Version 1.6.20 (built with libpng-1.2.38 and zlib-1.2.3.2)
  Changed local variable "write" to "wwrite" in inffast.c (zlib) to avoid
    shadowed declaration warning.

Version 1.6.19 (built with libpng-1.2.37 and zlib-1.2.3.2)
  Added missing braces that cause an incorrect png_error() to be issued.

Version 1.6.18 (built with libpng-1.2.37 and zlib-1.2.3.2)
  Removed extra FCLOSE(fpin) and FCLOSE(fpout) in the first Catch{} block,
    since they get removed anyway right after that (hanno boeck).
  Define PNG_NO_READ|WRITE_cHRM and PNG_NO_READ_|WRITEiCCP in pngcrush.h
    and reordered pngcrush.h

Version 1.6.17 (built with libpng-1.2.36 and zlib-1.2.3.2)
  Defined TOO_FAR == 32767 in deflate.c (again).  The definition
    has continually been inadvertently omitted during zlib updates
    since pngcrush version 1.6.4.
  Revised handling of xcode files so at least we can get printout
    of IHDR values with "pngcrush -fix -n -v xcode.png".
  Moved ChangeLog.txt back into pngcrush.c so it does not get lost.
  Removed single quotes from the ChangeLog.

Version 1.6.16 (built with libpng-1.2.35 and zlib-1.2.3.2)
  Added -newtimestamp and -oldtimestamp options and changed
    default condition to timestamping the output file with
    the current time (i.e., -newtimestamp is default)
  If the -oldtimestamp option is used then the output file
    has the same timestamp as the input file.
  Added CgBI chunk detection.

Version 1.6.15 (built with libpng-1.2.35 and zlib-1.2.3.2)
  Fixes some missing typecasts on png_malloc() calls, patch from
    an anonymous reporter to the SourceForge bug tracker.
  Added -time_stamp option to change time stamping from default
    condition.

Version 1.6.14 (built with libpng-1.2.35 and zlib-1.2.3.2)
  Avoids CVE-2009-0040.

Version 1.6.12 (built with libpng-1.2.34 and zlib-1.2.3.2)

Version 1.6.11 (built with libpng-1.2.33 and zlib-1.2.3.2)
  Eliminated a memory leak in libpng with writing bad tEXt chunks.
