Fixed various rigging issues and implemented new features.

Specifically:
- Adjusted the position of the bones in the mesh (player model and view model) to better fit the mesh into the valve biped armature.
- Implemented bodygroups for the view model. It defaults to player 1's outfit, but player 2's outfit is also available.
- Split the "brow" shape key into "brow_right" and "brow_left" to allow for more customization with the facial expressions.
- Removed excess hitboxes from the view model, in hopes that it will optimize performance.
- Tweaked the jigglebones for the glove straps. Hopefully their movement is now slightly more believable.

Initial addon creation.