Activated deferred shader override to support specular occlusion
Modified all Standard terrain shaders to new lighting model StandardRust
Added occlusion to terrain shader from composite normal map; used for ambient and light specular term
Settled on specular color instead of specularity
Improved ultra low quality level-of-detail for non-pvt path; now closer to textured version
Legacy parallax view vector on all terrain shaders; only affects pvt and legacy