RFC: removal of glGet*

This is a series to unify our matrix handling between GL and GLES. It also drops slow glGet calls in the GL pipeline and keep track of that on CPU.

There are some minor glGet for viewport left, but those are not run by default. If you feel advantages, run xbmc on a remote GLX session. It should run quite nicely on ethernet.

I've not tested this on GLES yet, so jenkins build this please.