Log Message:
Update to 1.2.33rc02, fixing a security problem.

version 1.2.33beta01 [October 6, 2008]
  Revised makefile.darwin to fix shared library numbering.
  Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
    in example.c (debian bug report)

version 1.2.33rc01 [October 15, 2008]
  No changes.

version 1.2.33rc02 [October 23, 2008]
  Changed remaining "key" to "png_ptr->chunkdata" in \ 
png_handle_tEXt()
    to avoid memory leak after memory failure while reading tEXt chunk.`