Added new customs to handle several collision variables and connected
those that matched existing blender conventions to those value items.
added max linear and angular velocity custom values to the ui
corrected property for max velocity customs
Merge pull request #154 from Ghostwalker71/feature/collision

Feature/collision
Updated setting file path for textures that can not be located due to
being inside compressed library.
version 12-83 nif import with textures
fix for material naming of version 12-83 nif mesh objects, added more
variables to import code.
further progress and clean up for 12-84 nif import and some work on
export
Added Custom values for nif version, user version, and user version 2.
renamed a few variables
Slight redesign of texture import to reduce duplicated code
Reconnect NiTextureProperty using the revised texture import
Created a block in nif_common to convert the nif version Uint hex to
user readable string.
Added version customs, and updated import and export to better handle
current nif files