This is due to the removal of huge inefficiencies in the loop_point(), return_cpmg_frqs() and
return_spin_lock_nu1() functions of the specific_analysis.relax_disp.disp_data module. Two new
functions return_cpmg_frqs_single() and return_spin_lock_nu1_single() have been introduces to pull
out the nu_CPMG and spin-lock field strengths for a given experiment and spectrometer frequency.
This avoids calling the loop_exp() and loop_frq() functions from within loop_point() which itself
is often called inside a loop_exp() and loop_frq() sequence.
