- Update to new upstream release 1.8.13:
* Made "-reduce" the default behavior. Removed obsolete options
"-plte_len", "-cc", "-nocc", "-double_gamma", "-already_crushed",
and "-bit_depth".
* Added "-speed" option; it avoids using the AVG or PAETH filters
which are slower to decode.
* Made "-force" force output even when the IDAT is larger, and
added "-noforce" option; "-noforce" is now the default behavior.
* Added "-warn" option, to show only warnings.
* Changed default verbosity from 1 (normal) to 0 (quiet). Use "-v"
to get the previous default behavior and "-v -v" to get the
previous "verbose" behavior. The "-s" (silent) and "-q" (quiet)
options behave as before.
- Remove pngcrush-systemlib.diff: not needed anymore.
- Add package source verification. (forwarded request 539164 from vilene)