Always use local arrays, which has been the default behavior
for a long time.

instead of memset to zero in png_read_png().

They were only useful for obtaining compatibility for old applications
that used libpng-1.0.x versions prior to the implementation of "free_me".

except in pngconf.h where they can be used to request that
PNG_FEATURE_SUPPORTED not be defined.

It does not seem to promise any benefit to libpng.

To try this, configure libpng using PNG_USE_MEMSET_LOOP.  Initial testing
with pngcrush was not promising, although it does save a hundred bytes or
so of executable size.

1. Modify project(PNG) to project(PNG C) to avoid search for C++ compiler
2. set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS true) and fix end conditionals
from ugly else(FOO AND BAR) endif(FOO AND BAR) to else() endif()
3. Add missing include_directories() for ZLIB_INCLUDE_DIR
4. Created CMake options to allow configurable building of STATIC or SHARED
libpng, both default on.
5. Modified PNG_DEBUG to default to false?
6. Fix installation of static/shared libraries so DLL goes in prefix+/bin,
all others in prefix+/lib

to reflect the new set of files in the distribution.

lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt,
and the "noconfig" files have been removed from the distribution.

It had been put inside the png_debug2() statement.

PNG_UNKNOWN_CHUNK_SUPPORTED should be PNG_HANDLE_AS_UNKNOWN_SUPPORTED.

Putting them ahead of the test for png_ptr==NULL so the debug
statements accuratly reflect the fact that the function was entered.

in pngwutil.c, that was recently added by mistake.

in libpng.3 and png.h

Previous log message is wrong, should say update configure scripts
instead of revert...