Log Message:
Version 0.7.6
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 * Upgraded libpng to version 1.6.21.
 ! Fixed an assertion failure in the image reduction code.
!! Fixed various security-sensitive defects in the BMP decoder.
 ! Fixed a benign uninitialized memory read in the GIF decoder.
 ! Fixed a build failure occurring under the Estonian (et_EE) locale.
 ! Fixed a build failure occurring on Mac OS X, FreeBSD, and possibly
   other systems that lack POSIX-compliant high-resolution timestamps.
 ! Fixed a typo causing build failures in 32-bit ANSI C compilation.