Make sure the player node's visibility cascades
Apply animations to bones manually

Couple reasons for this:

* This paves the way for allowing animations specified in other skeletons to
be applied to the character (NPCs and certain creatures can have multiple
animation sources, but Ogre is incredibly strict when it comes to sharing
animations between skeletons).

* It will allow for entities to be animated based on the character's skeleton,
without having to duplicate the mesh for each skeleton it can be used on.

This doesn't impact Ogre's ability to efficiently deform skinned meshes, nor
does it get in the way of hardware skinning.
Avoid handling animation states

We don't need them anymore
Don't share skeleton instances between bounded parts on an NPC

However, a skeleton instance will still be shared between entities in an entity
list.