Done with my edits. Dusk got ahold of me on IRC and sent me his build first, so his changes are in too.

There's one glaring bug I can't fix: I re-added Gez's sliding doors, but I can't for the life of me figure out how to get them to work. By all means, they seem as if they should (I've made 3DMidTex polydoors like this before), but they don't. Infiniblocking and HOMs still occur.
Still, there are a few things added & fixed, including fixed accuracy values for weapons w/casings (consider me neutral on whether casings stay or not), fire deaths, improved Gatekeeper fight, fixed Rifle and Grenades, and lots o' misc fixes. Should be slightly more sane now, I hope.

[EDIT] Added a new Hell skybox, too. It's by a bloke named "The Mighty Pete" and edited by Phi108. Got it from
this thread (it's the Plutonia E3 sky).