Log message:
Recursive bump for png-1.6.

Log message:
Version 1.7.47 (built with libpng-1.5.13 and zlib-1.2.7)
  Do not do the heuristic trials of the first 10 methods when -brute is
    specified, because it did not save time as I hoped.
  Fixed a mistake in 1.7.45 and 1.7.46 that caused the output file to
    not be written.

Version 1.7.46 (built with libpng-1.5.13 and zlib-1.2.7)
  Moved the new level 0 methods to the end of the trial list (methods 137-148)

Version 1.7.45 (built with libpng-1.5.13 and zlib-1.2.7)
  Added method 0 (uncompressed). "-m 0" now simply turns on method 0.
  Added "-try10" option that has the same effect that "-m 0" \ 
previously did,
    namely to try only the first ten methods.
  Inserted new methods 17 through 21 with zlib level 0.
  Do the heuristic trials of the first 10 methods when -brute is specified,
    to get quickly to a small solution, so we can bail out of most of the
    remaining trials early. Previously these 10 methods were skipped during
    a -brute run.
  Removed the "-reduce" line from the help screen when \ 
PNGCRUSH_COUNT_COLORS
    is disabled.

Log message:
Version 1.7.44 (built with libpng-1.5.14 and zlib-1.2.7)

Version 1.7.43 (built with libpng-1.5.13 and zlib-1.2.7)
  Added "remove(inname)" before "rename(outname, inname)" \ 
when using the "-ow"
    option on CYGWIN/MinGW because "rename()" does not work if the \ 
target file
    exists.
  Use the bundled "zlib.h" when PNGCRUSH_H is defined, otherwise use the
    system .

Version 1.7.42 (built with libpng-1.5.13 and zlib-1.2.7)
  Use malloc() and free() instead of png_malloc_default() and
    png_free_default().  This will be required to run with libpng-1.7.x.
  Revised the PNG_ABORT definition in pngcrush.h to work with libpng-1.7.x.
  Revised zutil.h to avoid redefining ptrdiff_t on MinGW/CYGWIN platforms.

Log message:
Changes 1.7.41:
* Reverted to version 1.7.38.  Versions 1.7.39 and 40 failed to open an
  output file.

Log message:
Drop superfluous PKG_DESTDIR_SUPPORT, "user-destdir" is default these days.

Log message:
Changes 1.7.38:
* Bail out of a trial if byte count exceeds best byte count so far.
* Added -bail and -nobail options.  Use -nobail to get a complete report
  of filesizes.
* Added -blacken option, to enable changing the color samples of any
  fully-transparent pixels to zero in PNG files with color-type 4 or 6,
  potentially improving their compressibility.

Log message:
Version 1.7.37:
  Reverted pngcrush.c back to 1.7.35 and fixed the bug with PLTE handling.

Version 1.7.36:
  Reverted pngcrush.c to version 1.7.34 because pngcrush is failing with
    some paletted PNGs.
  Separated CFLAGS and CPPFLAGS in the makefile (with "-I" and \ 
"-DZ_SOLO"
    in CPPFLAGS)

Log message:
Changes 1.7.35:
* Removed FOPEN of fpout except for the last trial.  The open files caused
  "pngcrush -brute -e _ext.png *.png" to fail on the 10th file (about the
  1024th compression trial) due to being unable to open the output file.

Log message:
Changes 1.7.34:
* Compute and report sum of critical chunk lengths IHDR, PLTE, IDAT, and IEND,
  plus the 8-byte PNG signature instead of just the total IDAT data length.
  Simplify finding the lengths from the trial compressions, by replacing
  the write function with one that simply counts the bytes that would have
  been written to a trial PNG, instead of actually writing a PNG, reading it
  back, and counting the IDAT bytes.  The savings, while measurable, are
  not very significant -- The "-brute" and default pngcrush runs that I
  tried are between one and five percent faster.  Most of the time is
  expended in zlib compression of the IDATs, which is not affected by
  the change.
* Removed comments about the system library having to be libpng14 or earlier.
  This restriction was fixed in version 1.7.20.

Log message:
Changes 1.7.33:
* Ignore all ancillary chunks except during the final trial.  This can be
  significantly faster when large ancillary chunks such as iCCP are present.

Changes 1.7.32:
* Fixed bug introduced in 1.7.30: Do not call png_set_check_for_invalid_index()
  when nosave != 0 (otherwise pngcrush crashes with the "-n" option).