relax SVN archive

Created the new lib.nmr relax library module.

This currently has a few simple functions for converting between ppm units and Hertz or rad/s units.

Small fix for the documentation of the relax_disp.r2eff_read* user functions.

This is for both relax_disp.r2eff_read and relax_disp.r2eff_read_spin.

Added some R1rho data from Dmitry Korzhnev's Fyn SH3 domain.

This originates from the cpmg_fit software and is published data.

Small comment fix.

Added the 'NS MMQ 3-site' parameters to the optimisation section of the dispersion chapter of the manual.

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.