First working version of 'external fitter'. SyncFit must be fixed.
Starting to write documentation
Working on Nelder Mead code and docu
Getting the docu in shape
Introduced a custom MiniFunc decorator for the SnyFitContainer

This step has become necessary to keep the SyncFit container functional
given the slightly changes structure of the OneDFit object, caused by the
introduction of external fitters.

In the future, the SyncFit-machanism should be more smoothly integrated
with the rest of funcFit.
extend changelog
getting the docu in better shape
Merged branch 'extFitter' to enable external fitters.

The 'external Fitter' is introduced to work in the direction of
separating the fitting and model code for further algorithms.