Added NiGeometry::ApplyTransforms function to automatically zero out the...

Added NiGeometry::ApplyTransforms function to automatically zero out the transforms of a mesh and apply them to its vertices.
Added NiGeometryData::Transform function to apply an arbitrary transform to all vertices and normals of a mesh (used by above).
Added NiNode::PropagateTransform function to apply a NiNode's local transform to its children and then zero it out.
Fixed NiTriShapeData to properly set numTriangles when SetTriangles is called.
NiGeometry::BindSkin function now automatically propagates transforms of NiNodes between the root and the meshes and then applies those transforms to the vertices, making the NiSkinData overall transform unnecessary.
Removed "set root to scene root" option as it is no longer necessary.