add_empty_as_parent.py

- Michel's linux test builds with Python 2.3.x were crashing.  This of course shouldn't happen even when Python isn't installed in the system.  The problem was much probably some uninitialized internal type needed by the Mathutils module and the "fix" is stupid.

Moving the registration of Mathutils module in Blender.c to the end of the list solves the crash here.