added convergence check:
	* self.g holds reference to TMinuit object, which is required to maintain access to gMinuit
	* gMinuit.fCstatu checked for convergence
	* convergence status stored in self.converged
* reimplemented the edge parameters, fixing according to wrange. This should be improved!
* added ability to take functions in addition to numbers for fixparms and setparms.
* cosmetic changes to output histograms: axis titles, legend, text panels with sigma values, identifiers for non-convergence, etc.