[libpng16] Update "last changed" dates in recently-patched files.
[libpng16] Imported from libpng-1.6.9beta01.tar
[libpng16] Bump version to 1.6.9beta02
[libpng16] Removed config-generated "compile" file
[libpng16] Fixed typo in CHANGES and ANNOUNCE (autoconf version 2.69, not 2.59)
[libpng16] Added checks for libpng 1.5 to pngvalid.c.  This supports the use of

this version of pngvalid in libpng 1.5
[libpng16] Merged with pngvalid.c from libpng-1.7 changes to create a single

pngvalid.c