[png-mng-implement] libpng-1.5.0beta44 is available

[Glenn Randers-P. <gl...@gm...>]

libpng-1.5.0beta44 is available from
ftp://ftp.simplesystems.org/pub/png-group/src
and from
http://libpng.sf.net/index.html

The work on pngvalid.c is by John Bowler.

Version 1.5.0beta44 [August 11, 2010]
  Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for
    installing libpng in /usr/lib64 (Funda Wang).
  Revised CMakeLists.txt to put the man pages in share/man/man* not man/man*
  Revised CMakeLists.txt to make symlinks instead of copies when installing.
  Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
  Implemented memory checks within pngvalid
  Reformatted/rearranged pngvalid.c to assist use of progressive reader.
  Check interlaced images in pngvalid
  Clarified pngusr.h comments in pnglibconf.dfa
  Simplified the pngvalid error-handling code now that cexcept.h is in place.
  Implemented progressive reader in pngvalid.c for standard tests
  Implemented progressive read in pngvalid.c gamma tests
  Turn on progressive reader in pngvalid.c by default and tidy code.

Glenn