Log Message:
Update to 1.5.13:

Version 1.5.13beta01 [August 8, 2012]
  Do not compile PNG_DEPRECATED, PNG_ALLOC and PNG_PRIVATE when __GNUC__ < 3.
  Removed references to png_zalloc() and png_zfree() from the manual.
  Revised PNG_FP_EXPORT and PNG_FIXED_EXPORT macros to avoid generating
    lone semicolons (patch ported from libpng-1.6.0beta11).

Version 1.5.13beta02 [September 10, 2012]
  Corrected handling of the image array and the row_pointers array in example.c
  When png_set_filler is used to strip a filler channel during write, the
    code prior to 1.5 would ignore the case where the output required an
    alpha channel or when the output was a palettized PNG.  In libpng-1.5 the
    ignorance was lost and libpng proceeded to strip the channel resulting
    in a bad (potential memory overwrite) failure later.  This reverts
    the behavior to the pre-1.5 state but issues a warning. libpng-1.6 is
    expected to issue an error on the erroneous png_set_filler call.
  Use png_memset() consistently (pngmem.c contained some bare "memset" \ 
calls).

Version 1.5.13rc01 [September 17, 2012]
  No changes.

Version 1.5.13 [September 27, 2012]
  No changes.