fix for HalfSpaceBV compound

Added one unknown float to the end of "HalfSpaceBV" compound as it seems that it has four unknown bytes after "Center". Problem reported at niftools forum http://niftools.sourceforge.net/forum/viewtopic.php?p=28704#p28704
Fixed error in Tangents and Bitangents lines.
Merge pull request #16 from ttl269/feature/HalfSpaceBV-compound-fix

fix for HalfSpaceBV compound
Preparing for release
Merge pull request #17 from niftools/release/0.7.1.0

Release/0.7.1.0
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