Classes under "rulesets" have been moved to "rules", and split up into
futher subdirectories matching their library. As a result we can now
better separate the python bindings, so that things that belongs to the
simulation are separeted from things that belongs to the ai.
The script is copied from the GoogleMock project and adapted
to instead generate stubs.
Two stub files are generated, one being named *_custom.h.
Any custom behaviour can be added to the latter, since it won't be
regenerated when the stub is recreated.