Cube registry finished and working!
Added some abstraction.
Moved the player model cache into it's own class.
Removed item models. Items now use the same model as player equipment.
Added a model renderer for the bow skin.
Small code cleanup.
More code cleanup.
Made a class for all client side skin operations.
Added Smart Moving support.
Fixed NPE when rendering the player.
Fixed skirts getting messed up when they player is sneaking.
Build 0.23.0
Merge branch 'develop'

* develop:
  Build 0.23.0
  Fixed skirts getting messed up when they player is sneaking.
  Fixed NPE when rendering the player.
  Added Smart Moving support.
  Made a class for all client side skin operations.
  More code cleanup.
  Small code cleanup.
  Added a model renderer for the bow skin.
  Removed item models. Items now use the same model as player equipment.
  Moved the player model cache into it's own class.
  Added some abstraction.
  Cube registry finished and working!