TFitterMinuit

 Default constructor . Srategy and tolerance set to default values.

 Constructur needed by TVirtualFitter interface. Same behavior as default constructor.

 initialize setting name and the global pointer

 create the minimizer engine and register the plugin in ROOT 

 destructor - deletes the minimizer and minuit fcn
 if using TVirtualFitter one should use Clear() and not delete() 

 do chisquare calculations in case of likelihood fits 

 clear resources for consecutive fits

 perform minimization using Minuit2 function
 use always strategy 1 (2 is not yet fully tested)

 minimize (call DoMinimization() and analyze the result

 execute the command (Fortran Minuit compatible interface)

/ study the function minimum      

 fix the paramter
   std::cout<<"FixParameter"<<std::endl;

 get the error matrix

 get error matrix element

 get fit errors 
   std::cout<<"GetError"<<std::endl;

 number of total parameters (ugly interface)

 number of variable parameters

 parameter error
   std::cout<<"GetParError"<<std::endl;

 parameter value
   std::cout<<"GetParameter"<<std::endl;

 get all parameter info (name, value, errors) 
   std::cout<<"GetParameter(Int_t ipar,char"<<std::endl;

   return name of parameter ipar

 get fit statistical information
   std::cout<<"GetStats"<<std::endl;

   std::cout<<"GetSumLog"<<std::endl;

 query if parameter ipar is fixed

 print the fit result

 release a fit parameter

 set fit method (i.e. chi2 or likelihood)
 according to the method the appropriate FCN function will be created   

 set (add) a new fit parameter passing initial value,  step size (verr) and parametr limits
 if vlow > vhigh the parameter is unbounded
 if the stepsize (verr) == 0 the parameter is treated as fixed   

 override setFCN to use the Adapter to Minuit2 FCN interface
*-*-*-*-*-*-*To set the address of the minimization function*-*-*-*-*-*-*-*
*-*          ===============================================
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*

*-*-*-*-*-*-*To set the address of the minimization function*-*-*-*-*-*-*-*
*-*          ===============================================
     this function is called by CINT instead of the function above
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*

 class takes the ownership of the passed pointer
 so needs to delete previous one 

 create a chi2 FCN object

 create an extended chi2 FCN object 
 used in the case of errors both on the coordinates and the value (case of a graph fit)

 create a binned likelihood FCN

 methods needed by derived classes 

 set minimum tolerance to avoid having clients (as TGraf::Fit) setting tolerances too small