relax SVN archive

Fix for loading a seriesTab formatted intensity, and getting the ID for the following GUI elements.

Fix for bug #21076, (https://gna.org/bugs/?21076) - When loading a multi-spectra NMRPipe seriesTab file through the GUI, several Error messages occur.

The relax_disp.r2eff_read_spin user function now can handle offset data in the file.

If the new offset_col argument is set and disp_point_col is not, then the file being read can
contain the spin-lock offset information rather than the spin-lock field strength values. This is
only for R1rho-type data.

The relax_disp.spin_lock_offset user function now uses the lib.nmr module.

This is for converting between ppm and rad/s units.

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.