relax SVN archive

Wrote the interface for the n_state_model.pivot_point() user function.

Added the setting of the pivot point to the 5 state xz plane system test.

Fixes for all the unit tests of the maths_fns.n_state_model func() method.

The 'full_in_ref_frame' arg was required.

Fix for the 5-state xz plane system test.

The reference frame arg had to be set within the test.

The maths_fns code now uses the 'full_in_ref_frame' variable.

The 'full_in_ref_frame' is now correctly created.

Bug fixes for the N-state model minimise() function.

The variable is 'cdp.ref_domain', not 'cdp.ref'!

Bug fix for the echoing of the n_state_model.model() user function.

Modified the N-state model minimise() function to generate the 'full_in_ref_frame' variable.

Added the ref arg to the specific_fns.n_state_model.model_setup() function.

The ref domain now is stored in the variable 'ref_domain' in the current data pipe.