Pushed the mtrl tracking code down through the entire game render.

Pushed the mtrl tracking code down through the entire game render.
Eliminated most of the client state enable/disable.
Fixed a couple materials with zero emission alpha, which is non-default but does nothing.
Minimized billboard transformations.

git-svn-id: https://s.snth.net/svn/neverball/branches/gles@3549 78b8d119-cf0a-0410-b17c-f493084dd1d7