Cleaning Handle Stuff
Allow Tasks/Await
Handles for IPhysAggregateInstance (we're calling it PhysicsGroup)
UTIL_Remove for client
Added Entity.PhysicsGroup property
PhysicsGroup class
Interop: When getting a Handle class, we send native IntPtr but we recieve Handles
Updating Binds
Tests to see if accessing PhysicsGroup after entity is deleted causes a crash