Merge pull request #426 from ImperatorPrime/master

Removed unused _USRDLL define and dependent code.
[MP] Add the maplist cmd as a real command and not just tied to callvote map.
[SP] Clean up renderer files, removed ununsed files
[SP] Clean up some unused code, defines, includes
[MP] Clean up some unused code, defines, includes
[MP] Try ioq3's version of the video record desync fix.
Though technically its not any different.
[SP] Merge some g_client cleanup/rewrite stuff to SP from MP.
Removed _NO_PCH and _IMMERSION references.

_NO_PCH will always be true, and _IMMERSION references nothing, so out
they go.