These are the functions in the specific_analyses.relax_disp.disp_data module. The
return_cpmg_frqs() and return_spin_lock_nu1() functions now no longer take the spins and spin_ids
arguments. Instead they determine if a dispersion point exists for the given experiment and
spectrometer frequency using the intensity keys and data in the base of the data pipe.
The specific_analyses.relax_disp.disp_data.loop_*() functions now accept the return_indices argument
which if True will cause all of the relevant experiment type, spectrometer frequency, dispersion
point, and relaxation time indices to be returned.
The behaviour of the loop_point() method is now different. Instead of looping over all possible
dispersion points, it only loops over those points present for the given experiment and spectrometer
frequency. This change allows for many simplifications and latent bug fixes in the dispersion
analysis.
