Added user function: relax_disp.set_grid_r20_from_min_r2eff.
Feature request: #3151, (https://gna.org/support/index.php?3151) - User function to set the R20 parameters in the default grid search using the minimum R2eff value.
Authored by: tlinnet 2014-04-25
Parent: [r22856]
Child: [r22858]
