Update broken or inconsistent project and wiki urls * README, doc/interpreter/contrib.txi, etc/HACKING, etc/README.MacOS, etc/README.MinGW, etc/README.devel: Update urls to use the octave.org domain. * doc/faq/OctaveFAQ.texi, scripts/miscellaneous/info.m: Replace broken links to the manual and help mailing list. * doc/faq/OctaveFAQ.texi, etc/PROJECTS, etc/README.MacOS: Update wiki urls to short naming scheme. * doc/interpreter/contrib.txi, scripts/help/unimplemented.m: Make Octave-Forge project urls consistent. * src/version.h.in: Update url to contribution page.