apply a suggestion from Axel to remove a conflict of two TF1 constructor, when a TString was passed for the formula name.  Using an explicit constructor for ParamFunctor the compiler will not perform implicit conversion from TString to ParamFunctor, but to TString to const char *.
apply a suggestion from Axel to remove a conflict of two TF1 constructor, when a TString was passed for the formula name. 
Using an explicit constructor for ParamFunctor the compiler will not perform implicit conversion from TString to ParamFunctor, but to TString to const char *.


git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@26722 27541ba8-7e3a-0410-8455-c3a389f83636

dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,dawehner/root,bbannier/ROOT,dawehner/root,bbannier/ROOT,dawehner/root,bbannier/ROOT