[MP] Merge ioquake/ioq3@b3f36fc8308de0be9cdf865b20825e91a07149b0

Allow weapon marks on triangle meshes (default: disabled), patch by Oliver McFadden. http://bugzilla.icculus.org/show_bug.cgi?id=3774

Refs #516, doesn't fix because you said you wanted those other things (not sure how plausible they are from engine pov)