MGFX Large Shader Fix

The first thing this does is fix an overflow in loading large shaders.  I have run into two cases where debug shaders can be > 65K and overflow the 16bit size.  This fixes my miscalculation restoring that to a 32bit integer, increments the MGFX version, and rebuilds the stock effects.

Second I took the time to remove old shader code files that are no longer used by the runtime.