Blender Git Loki

BGE: Fixing the memory leaks reported when the BlenderPlayer exits.

They were caused by not having a free_windowmanager_cb set and by not having registered SpaceTypes, which meant data allocated for thosse SpaceTypes could not be freed. These were solved by defining a free_windowmanager_cb for the player that just frees wmWindows, and by making sure we only allocate memory for registered SpaceTypes.