PNG and MNG/JNG image formats: home site

Libpng-1.2.21 and libpng-1.0.29 have been released and are available at
ftp://ftp.simplesystems.org/pub/png/src
and at
http://libpng.sf.net  

  Fixed various mistakes reported by George Cook and Jeff Phillips:
  logical vs bitwise NOT in pngrtran.c, bug introduced in 1.2.19
  16-bit cheap transparency expansion, bug introduced in 1.2.19
  errors with sizeof(unknown_chunk.name), bugs introduced in 1.2.19
  <= compare with unsigned var in pngset.c, should be ==.
  Removed some extraneous typecasts.
  Fixed potential out-of-bounds read in png_handle_pCAL(), png_handle_sCAL(),
    png_push_read_tEXt(), png_handle_iTXt(), and png_handle_ztXt() ("flayer"
    results reported by Tavis Ormandy).
  Remove some PNG_CONST declarations from pngwutil.c to avoid compiler warnings
  Revised makefiles to update libpng.pc properly.

Glenn