relax SVN archive

Bug fix for the setup of MC simulations of the diffusion tensor.

MC sims were not working when all parameters except for the diffusion tensor are fixed.

Extended the OMP model-free system test to run MC sims for the diffusion tensor.

Improvements for the reload_pdb() method.

Now the system path is searched for the PDB file. This allows the system tests to pass when not
running from the installation path.

Bug fix for the generate_vector_residues() function.

Now the negative vector actually is negative! It was previously the same as the positive vector.

Bug fix for the generate_vector_dist() function.

Now the diffusion tensor and cone geometric objects are correctly created!

Fixes for Tyler's peptide system test.

The residue was 111 in the PDB but 211 in the results file, and the spin was unnamed.

Fix for the return_units() method. The spin and spin_id args are now accepted.

Fixes for all the N-state model optimisation unit tests.

Removed a debugging print out.

Fix for the func_2domain() method for the N-state model tensor reduction code.