Blender Git Loki

Fixing a crash on exit when using the Blenderplayer on win32. When free_blender() was freeing main, main was garbage since the blend file data was already freed. So, I just replaced free_blender) with IMB_exit() and free_nodesystem(). Using free_blender() worked when I was in Linux running tests. That or I'm just gong crazy. ;)