Optimize Matrix::SetRotatePart. Remove code duplication and todo in that functionality. Optimize float4x4::SetTranslatePart.
Add Quat::Slerp benchmark.
Enable SetRotationAxis3x3 in Matrix.inl.
SSE-optimize some Quat functions.
Minor doc & whitespace.
Update erroneous doc relating to NaNs. "nan != nan" returns true!