Havok blocks update

@neomonkeus @skyfox69 @jonwd7 @Ghostwalker71 @throttlekitty @nexustheru @amorilia Update of some havok blocks.
1. Most of changes are related to constraints. Changes cause that Nifskope don't render any havok constraints - structure of `bhkConstraint` block has been modified. **If this will be merged it will require to modify Nifskope's code too.** [See](https://github.com/ttl269/nifxml/commit/7c6fa75e92571bc63196de30b05f394c02c2f807)
2. Added three new unknown Skyrim materials. Little modification in `bhkRigidBody` block. [See](https://github.com/ttl269/nifxml/commit/4c4fd47092599689c2f28f501d2535853b6bcaae)
3. Extended the description of `Unknown Int 2` in `NiGeometryData`. [See](https://github.com/ttl269/nifxml/commit/281e1f9c4c503a0f3944bc614a28a6f123cb13a4)