[libpng16] Revised example.c to illustrate use of PNG_DEFAULT_sRGB and

PNG_GAMMA_MAC_18 as parameters for png_set_gamma().
[libng16] Revised contrib/tools/png-fix-too-far-back.c to check all compressed

chunks known to libpng.
[libpng16] Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c
[libpng16] Imported from libpng-1.6.3beta09.tar
[libpng16] Change "png-fix-too-far-back" to "pngfix" inside pngfix.c

for error messages, etc.
[libpng16] Bump version to 1.6.3beta10
[libpng16] Updated documentation to show default behavior of benign errors

correctly.
[libpng16] Only compile ARM code when PNG_READ_SUPPORTED is defined.
[libpng16] Fixed undefined behavior in contrib/tools/pngfix.c and added new

strip option. pngfix relied on undefined behavior and even a simple change from
gcc to g++ caused it to fail.  The new strip option 'unsafe' has been
implemented and is the default if --max is given.  Option names have
been clarified, with --strip=transform now stripping the bKGD chunk,
which was stripped previously with --strip=unused.
Added all documented chunk types to pngpriv.h
[libpng16] Unified pngfix.c source with libpng17.
[libpng16] Imported from libpng-1.6.3beta10.tar
[libpng16] Imported from libpng-1.6.3rc01.tar
[libpng16] Updated manual to mention that warnings about iTXt language tag

and translated keyword are no longer issued when these are empty, which
is allowed by the PNG specification.
[libpng16] Added "/* SAFE */" comments in pngrutil.c and pngrtran.c

where warnings may be erroneously issued by code-checking applications.
Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
[libpng16] Revised "/*SAFE*/" comment in pngrutil.c
[libpng16] Imported from libpng-1.6.3.tar
[libpng16] Bump version to 1.6.4beta01