relax SVN archive

Added proper pseudo-atom support for the RDCs in the N-state model analysis.

This involves a number of changes. The pseudo-atom specific functions ave_rdc_tensor_pseudoatom()
and ave_rdc_tensor_pseudoatom_dDij_dAmn() have been added to the lib.alignment.rdc module. These
simply average the values from the equivalent non-pseudo-atom functions. The return_rdc_data()
function in the specific_analyses.n_state_model.data module has been modified to assemble the RDC
constants and unit vectors for all members of the pseudo-atom and add these to the returned
structures, as well as a new list of flags specifying if the interatom pair contains pseudo-atoms.
The N-state model target function and gradient have been updated to send the pseudo-atom data to the
new lib.alignment.rdc module functions.

Added the return_id argument to the pipe_control.mol_res_spin.pseudoatom_loop() function.

This will then yield both the spin container and spin ID string. This mimics the spin_loop()
function.

Modifications for the pyrotartaric anhydride system test script.

The grid search now is much quicker, and the RDC correlation plots are now sent to DEVNULL.

Added all of the pyrotartaric anhydride RDC generation scripts and files.

This is simply for reference and reproducibility.

Created two new system tests based on the new pyrotarctic anhydride long range (1J, 2J & 3J) RDC data.

The first (N_state_model.test_pyrotartaric_anhydride_rdcs) optimises an alignment tensor using long
range signed RDC data. The second (N_state_model.test_pyrotartaric_anhydride_absT) optimises an
alignment tensor using long range absolute T (J+D) data. Both test long range data together with
methyl group pseudo-atom data.

Renamed the propylene carbonate files to the correct name of pyrotartaric anhydride.

Added a PDB file and RDC values (and absolute J+D and J) for propylene carbonate.

This will be used for testing of pseudo-atoms in the N-state model analysis.

Created the pipe_control.mol_res_spin.pseudoatom_loop() function.

This is used to loop over the spin containers corresponding to a given pseudo-atom.

Created the pipe_control.mol_res_spin.is_pseudoatom() function to simplify pseudo-atom handling.

Shifted the RDC and PCS assembly methods from the main class to the data module for the N-state analysis.