relax SVN archive

Editing of the introduction section of the dispersion chapter of the manual.

Fix for a bug in the R2 parameter constraints introduced in the previous commit (r21778).

This was debugging code which was accidentally committed.

The pC parameter constraints are now implemented for the 3-site dispersion models.

The new constraints are 0 <= pC <= pB.

Clean up of the parameter lists in the dispersion model table of the manual.

Clean up of the 'NS R1rho 3-site' model names in the manual.

The word 'branched' has been removed and the notation now matches the 'NS MMQ 3-site' models.

Renamed the 'MQ CR72' dispersion model to 'MMQ CR72'.

The model is designed by Korzhnev et al., 2004 for proton-heteronuclear SQ, ZQ, DQ, and MQ data
(or MMQ data), so the change is logical as the model is not just for MQ data.

Removed the 'MMQ 3-site branched' and 'MMQ 3-site linear' models from the to do list in the manual.

These two dispersion models are now implemented.

Renamed all remaining instances of 'MMQ 2-site' to 'NS MMQ 2-site'.

This is simply changing variable, method and module names.

Renamed the 'MMQ 2-site' model to 'NS MMQ 2-site'.

This is so that the name matches those of the 'NS MMQ 3-site linear' and 'NS MMQ 3-site' models.

Created the Relax_disp.test_ns_mmq_3site_linear system test and modified Relax_disp.test_ns_mmq_3site.

The Relax_disp.test_ns_mmq_3site_linear system test uses the old data from the directory
test_suite/shared_data/dispersion/ns_mmq_3site/, as this had kAC = 0, now copied into the
ns_mmq_3site_linear/ directory. This system test uses the 'NS MMQ 3-site linear' model.

The base data generated by cpmg_fit for the Relax_disp.test_ns_mmq_3site system test was modified so
that kAC is no longer 0, but set to 1000. This should properly test the 'NS MMQ 3-site' model.