strings (skybox and *progs). skybox is easy to take care of (aditional parse
functions), but I haven't yet decided what to do with *progs. Also, progs code
needs a bit of a cleanup, but that will come later.
progs engine no longer refers to any global vars. This alows for multiple progs
being loaded (NOTE: NOT multiple mods, but (eg) for various protocol
extensions) and, once the last couple of issues are taken care of, CSQC.