graphics/netpbm: Update to 10.80.00

• This moves netpbm to the advanced release series, which brings the port closer to what is available on OpenBSD, Fedora, Arch Linux, openSUSE, etc. and will let us get rid of patches for supporting newer libpng versions.
• The advanced release series is only available via an SVN checkout. Add two maintenance targets netpbm-version-check and netpbm-fetch to make fetching them easier. To generate release tarballs the sources are then tagged and committed to https://github.com/t6/netpbm
• Add STATIC option for linking all programs statically to allow running them in small chroots
• Add option to disable adding a Perl run dependency. Only a fraction of all programs need it. Some are compatibility shims for newer programs which should be used instead. The following programs require Perl: pamfixtrunc pbmtox10bm pgmcrater pnmflip pnmquant pnmquantall ppmfade ppmquant ppmrainbow ppmshadow
• Disable building svgtopam by default. It's the only program that requires libxml2 and is obsolete according to the author.
• Install manpages by default
• Allow running of the test suite via make test
• Headers have been moved to ${LOCALBASE}/include/netpbm. Fix ports that expect them to be in ${LOCALBASE}/include

Changes: https://raw.githubusercontent.com/t6/netpbm/v10.80.00/doc/HISTORY
PR: 219982
Reviewed by: mat
Exp-run by: antoine
Differential Revision: https://reviews.freebsd.org/D11157