relax SVN archive

The pipe_control.rdc.q_factors() function now properly handles pseudo-atoms.

If pseudo-atoms are present, then 2Da^2(4 + 3R)/5 normalised Q factor is skipped.

The N-state model specific check_rdcs() function now properly handles pseudo-atoms.

The stereochemistry auto-analysis can now accept a file of interatomic distances.

This is for better pseudo-atom support.

Updated the value checking for the N_state_model.test_absolute_rdc_menthol system test.

The pseudo-atoms are now properly handled so the result is now much better.

The interatom.unit_vectors user function now calculates the unit vectors for deselected containers.

This is useful for pseudo-atom handling where the interatomic containers to the pseudo-atom members
have already been deselected.

Renamed the interatomic_loop() function 'selected' argument to 'skip_desel'.

This is to match the spin_loop() function arguments.

Updated the menthol long range RDC data file to include pseudo-atom member distances.

An RDC error of 0.0 will now deselect the corresponding interatomic data container.

This can be used for simpler pseudo-atom handling.

The N_state_model.test_pyrotartaric_anhydride_absT system test now uses simplex optimisation to pass.

The Newton algorithm cannot be used as the gradients for T = J+D type data have not been implemented.

A RelaxError is now raised for the N-state model optimisation with gradients when T = J+D data is used.

The gradients for this data type are not implemented yet, so it is better to prevent the user from
using this.