relax SVN archive

Lots of updates to the rdc.read user function backend.

Fix for the id_match() method - there are no indices.

Shifted the id_match() method to the correct class!

Updated another N-state model system test script to the new rdc.read interatomic data design.

The generic_fns.interatomic.create_interatom() function now returns the created container.

This comes from the InteratomicContainer.add_item() method which now also returns the container.

Missing imports.

Renamed the interatomic function return_container() to return_interatom().

This is to make the name more unique.

Bug fix for a segmentation fault occurring during the model-free GUI test.

Flushing of the interpreter queue object is needed as some parts of the interface use asynchronous
user function calls.

Shifted some code from InteratomList.add_item() to generic_fns.interatomic.create_interatom().

This is to break a circular import problem.

The rdc.read user function backend is now adding the RDCs to the interatomic data containers.