Blender Git Loki

BPython:
- as proposed by Ton, default dir for menu enabled scripts is:
userhome/.blender/scripts if available or (using bprogname -- argv[0]),
blenderInstallationDir/.blender/scripts/ otherwise.
- moved a piece of code from BPY_interface.c to BPY_menus.c to get rid
of a linkage warning reported by J. Walton
-- added the first scripts to release/scripts:

We need time to get more scripts there, but the situation should improve
consistently from now on. Adding three export scripts: cal3d, directX, ac3d.
And one import: ac3d.