Final method2 implementation

Hcal 25ns reconstruction method2 implementation with fast fitter
Unfortunately, the constructor and destructor of TFitterMinuit are not thread safe. The constructor changes ```gMinuit2``` to point to this instance (an annoyance) and the constructor adds this object to a global list of 'special' objects. It is the latter which is unsafe. The destructor does the same but 'in reverse'. Therefore constructing and destructing instances of TFitterMinuit can lead to a crash.