removal of SkyrimMaterial

Replaced "SkyrimMaterial" by "Unknown Int" in NiGeometryData (how it got there?) and bhkCompressedMeshShape as both seems not be havok material definitions.
material remove from bhkMoppBvTreeShape

Removed material definition and replaced by Unknown Int.
Merge pull request #21 from ttl269/fix/SkyrimMaterial-removal

Fix/skyrim material removal