Fix for Fedora release 20 (Heisenbug)
method to set the initial range of an existing variable
fix PrintAllDefault method
fix bug in stressFit.cxx Now "Ok" is printed when ALL attempts converge to the minimum
Multiple modifications in stressFit.cxx: - switch from TVirtualFitter to ROOT::Math::Minimizer - successful trial means found minima is within predefined epsilon (before was arguments are close to the minimum's position). This modifies ROOTMARKS value - StatusPrint reports number of successes out of the trials number