cleanup of avatar collisions, prep for more ragdoll collisions

removal of paddle hands
particles use general sphere collision path against avatars
temp removal of skeleton self collision
cleaup: remove some unused collision code

remove CollisionInfo::_type
remove unused Avatar collision response stuff
comment out some code that works but will probably be replaced
move RagDoll to libraries/shared
fix some comments
Use NULL Shape* for non-colliding joints in Models
clearShapes(), rebuildShapes() need not be virtual
RagDoll keeps a pointer to list of shapes
Add simulationID to Model Shape and CollisionInfo
merge