Finished current cleanup/reorg.

Temporarily disabled logic for forward render of probes to avoid data mangle. TODO: fix up forward once deferred math is locked in
Split probe modes out into distinct environmental probe objects
Removed the probes from tracking their own baked cubemap file paths and instead have a pref store it
Removed old probe shaders and materials that aren't used now.
Fixed mLastConst memory leak by removing nono line.

Engine/source/T3D/lighting/skylight.cpp

@@ -171,8 +171,6 @@ void Skylight::updateProbeParams()
 
    setGlobalBounds();
 
-   mProbeInfo->mAmbient = LinearColorF(1, 1, 1, 1);
-
    mProbeInfo->mIsSkylight = true; 
    mProbeInfo->mScore = -1.0f; //sky comes first
 }