relax SVN archive

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.

Created the generic_fns.interatomic.create_interatom() function for creating interatomic data containers.

Added checks to the InteratomList.add_item() method to make sure that the spin IDs already exist.

Fix for the InteratomList.add_item() method.