relax SVN archive

This is a minor feature release which adds support the 'NS MMQ 3-site linear', 'NS MMQ 3-site',
'NS R1rho 3-site linear', and 'NS R1rho 3-site' relaxation dispersion models. There is also
improved support for R1rho data sets where multiple offsets and multiple spin-lock fields have been
collected for each spin.