Fix some file paths for msvc 2008
OpenGL2: Support GL_ARB_vertex_type_2_10_10_10_rev for normals/tangents/lightdirs
Fix crash in OpenAL when no input devices are available
OpenGL2: Small glsl shader optimizations, fixes, and cleanup.
Fix playback of stereo sounds in Base sound system

Already works correctly in OpenAL.
Merge remote-tracking branch 'ioquake3/master'

Conflicts:
	code/renderergl2/glsl/dlight_vp.glsl
	code/renderergl2/glsl/lightall_vp.glsl