relax SVN archive

The supported types will now be 'CPMG' and 'R1rho', as the fixed time verses full exponential curve
can be automatically determined by relax from what the user inputs.

The EXP_TYPE_* dispersion variables have all changed and many have now been lost. To support the
changes, the new specific_analyses.relax_disp.disp_data.loop_spectrum_ids() function has been
created. This is a loop over all spectrum IDs whereby the experiment type, magnetic field strength,
dispersion point, or relaxation time can be specified to isolate ID subsets.

Many of the specific_analyses.relax_disp.checks.check_*() has also been modified as their logic no
longer works. The auxiliary get_times() function has been added to create a per-experiment
dictionary of relaxation times so that the checks can be independent of the other dispersion
modules.