Main: TextureUnitState - drop reference to managed textures on unload
Main: TextureUnitState - drop reference to managed textures on unload

OGRECave/ogre,paroj/ogre,OGRECave/ogre,paroj/ogre,paroj/ogre,OGRECave/ogre,paroj/ogre,OGRECave/ogre,paroj/ogre,OGRECave/ogre