Import initial icns2png distribution.
Removed stuff of questionable origin and copyright/licencing.
Source: http://baghira.sourceforge.net/Goodies/icns2png.tar.bz2
Convert to Unix (LF) line endings
Build using png shared library by default
Fix formatting:
- use tabs and spaces properly
- remove * crud from licence statements
- remove extra whitespace
Fix typo in clean target of Makefile
Fix typo in release target of Makefile
Enable more warnings during building
Replace dependence on icondefs.h, mactypes.h and other mac headers with common.h
Accept CFLAGS and LDFLAGS from the environment
Add an AUTHORS file
Fix some warnings output by gcc -Wall
Use system zlib and libpng libraries
Prepare for converting from C++ to C since C has more compilers on more systems.
Update the URL to some sample OSX icons
Convert byteswap.cpp from C++ to C
Convert icns2png.cpp from C++ to C
Convert iconvert.cpp from C++ to C
Convert pngwriter.cpp from C++ to C
Fix gcc warning about unused variable dataCount
Fix memory leaks in pngwriter.c and icns2png.c