Adding players + lots more

Added BaseHuman class
Added PlayerEntity class
Added Player.GetEntity
Updated categories
Removed unused Game.mPlayer
Removed Game.ProcessInput
Moved Entity's Velocity/Accelerate functions to SceneNode
Fixed Player Movement, starting to work on Collisions tomorrow

Lua: Wrapped BaseHuman class
Lua: Wrapped PlayerEntity class
Lua: Added game.LoadTexture
Lua: Added player entity to BuildScene event

Going to sleep now. Last thing I did was started to work on
BaseHuman::CreateMovement