Blender Git Loki

fix BGE bug #8668: Behavior of os.getcwd() is not consistent between operating systems

Add a function GameLogic.expandPath() that works like Blender.sys.expandpath() and is also available in the BlenderPlayer.
Fix the game actuator in the BlenderPlayer to work like in Blender:
- try first to load the .blend from the current working directory
- if not found, try to load from the startup .blend or runtime base directory