[png-mng-implement] libpng-1.2.53beta02 is available

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

libpng-1.2.53beta02 is available from
ftp://ftp.simplesystems.org/pub/png-group/src/libpng12
and from
http://libpng.sf.net

version 1.2.53beta02 [February 6, 2015]
  Issue a png_error() instead of a png_warning() when width is
    potentially too large for the architecture, in case the calling
    application has overridden the default 1,000,000-column limit
    (fixes CVE-2014-9495 and CVE-2015-0973).
  Quieted some harmless warnings from Coverity-scan.

Glenn