Moved target function for curve fitting with scipy into specific_analyses.relax_disp.estimate_r2eff.
This will later include the backend specific_analyses.relax_disp.optimisation.estimate_r2eff() function and the code in the target_functions package.
The code in target_functions.relax_disp_curve_fit is a lot more than just a target function, so it doesn't really belong in this package.
This is also to isolate this experimental feature.
Authored by: tlinnet 2014-08-25
Parent: [r25242]
Child: [r25244]
