Add zero option to ExtraVectorsFlags to allow blender plugin to set the

value during export.

bhkBreakableConstraint update

1. Added PrismaticConstraint to list of available constraints in SubConstraint
2. Previously added enum "ConstraintType" renamed to "hkConstraintType"

Added structure of bhkBreakableConstraint. It seems that it is (and also bhkMalleableConstraint) some kind of "parent descriptor" for behavior for their "children" constraint which must be inserted within it. This inserted constraint in named "Sub Constraint", its type is determined by "Constraint Type" integer value. After this integer there is inserted complete constraint - one of allowed "common" constraints. And then there are inserted parameters specific for parent constrains (for example breakable one has "Threshold" and "Remove if Broken"). From vanilla nifs it seems that this "Sub Constraint" has always set its "Num Entities" to 2 but also both references to "Entities" are set to None. I think that this is probably because the relation between two rigid bodies this constraint is affecting is determined earlier - in "Entities" of parent constraint (bhkBreakableConstraint or bhkMalleableConstraint) and therefore it is not necessary (or it is forbidden?) to set references to entities also in "Sub Constraint".

bhkRagdollTemplate support

Added support for bhkRagdollTemplate block based on two .rdt files (.rdt file is a .nif file) located in Fallout3 directory "meshes/ragdollconstraint". It seems that game uses only file "Default.rdt". Second file "stiff.rdt" is unused and suspicious because in NiHeader it has User Version 2 set to 16 instead of 34 as all Fallout3 files (and also Default.rdt) have.
Can anybody check Fallout New Vegas files if there are present any .rdt files? It would be good to have more than 2 files for decoding. Or exists other games with these files?

NiSkinPartition unknowns removed

havok Materials and Layers update

Corrected order of materials in list of Skyrim materials to be sorted
ascending.

1. Added havok material definitions for Fallout 3. Only basic 31
materials defined. Function of other bits included in description.
2. Removed game prefix from havok material definitions.
3. Added havok layer definitions for Fallout 3.
Conflicts:
	nif.xml

Fallout3 Shader Properties update

Reverted names of two Unknowns in BSShaderPPLightingProperty to "Unknown Float 4" and "Unknown Float 5". Also renamed "Envmap Scale" in BSShaderProperty to "Environment Map Scale" and added its description of funtionality - it is same as "Environment Map Scale" in BSLightingShaderProperty - controls the intesity of the environment map.

Updated BSShaderProperty, BSShaderLightingProperty, BSShaderNoLightingProperty, BSShaderPPLightingProperty and SkyShaderProperty blocks for Fallout3. Added BSShaderFlags2 and their meanings.

Change `Unknown Float 2` to `Refraction Strength`

See: http://niftools.sourceforge.net/forum/viewtopic.php?f=8&t=5847

Num UV Sets split

Removed conditioned unknowns at end of NiSkinPartition block.

added billboard mode BS_ROTATE_ABOUT_UP

Added billboard mode called "BS_ROTATE_ABOUT_UP" - it has value 5. It is used in Skyrim and Fallout 3 nifs. Also works in Oblivion.

Changed type of ExtraVectorFlags from `bitflags` to `enum`.

Changed definition of "Num UV Sets" (for >= 10.0.1.0 only) and get rid of "BS Num UV Sets".
"Num UV Sets" defined as byte containing number of UV texture sets. Added definition of "Extra Vectors Flags" stored in byte. Only known function of that flags by that time is 4th bit representing flag for Tangents/Bitangents arrays - this is defined in bitflags type "ExtraVectorsFlags".
As there is no certainity that number of UV Sets can be stored in all 8 bits, I have left AND function on line 2731 where "arr1" is getting a number of UV Sets only from lower 6 bits (i.e. max number of UV Sets is 63). There is a note about that on line 2725 (although it is for old version 4.0.0.2).

Fix/skyrim material removal

Removed material definition and replaced by Unknown Int.

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

Release/0.7.1.0

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

Feature/rocksmith support

Tested with several Skyrim vanilla nifs containing effects and it looks ok. Also got load errors when using "!=0" syntax, so agree to use old syntax.

bhkMoppBvTreeShape and Build Type