image_width is now only set by a single function.
tweaked scancode inputs slightly. added support for printscreen binds.
changed the way gamma works. glsl gamma now used when running windows, or hardware gamma is not available. removed gl_contrast+gl_brightness.
q2 gamecode support no longer has a system componant. this means that ports only need the generic stuff.
misc tweaks to the d3d11 renderer.
added brief descriptions to many builtins. need to add comments to constants, globals, and fields too, somehow.
git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@4355 fc73d0e0-1445-4013-8a0c-d673dee63da5
