BoUT2: Add mirror vertex shader from game
BoUT2: Run mirror shader through ShaderConverter
BoUT2: Fix sincos for vs_3_0

Looks like ShaderConverter misses this difference.
BoUT2: Add text vertex shader
BoUT2: Run text vertex shader through ShaderConverter
BoUT2: Add toggle key to push subtitles into screen (breaks menu!!!)

Press 9 to toggle the depth of the subtitles, description of what the mouse is
over, etc.

This breaks the menus - all the text shifts to the right :(

I've been unsuccesful so far trying to dump out the textures in use... NFI what
I'm doing wrong.