Add new feature of Ini->shader constants.

These are specified in the .ini file, and are passed into the shaders, where they can be loaded and used in If statements.

This creates a new ShaderResourceView, which is attached to the shader right after SetShader.
Ignore vsglog files, so they don't get checked in.
Tweak shaders to use new .ini constants for HUD.

This allows people to set HUD at whatever depth they like, including popout or at screen depth.