rename directory -> Fit/Adapter (not restricted to Root)

Fit/Adapter/GSLLevenbergMarquardtMinimizer.cpp

Fit/Adapter/GSLLevenbergMarquardtMinimizer.h

Fit/Adapter/GSLMultiMinimizer.cpp

Fit/Adapter/GSLMultiMinimizer.h

Fit/Adapter/GeneticMinimizer.cpp

Fit/Adapter/GeneticMinimizer.h

Fit/Adapter/IFunctionAdapter.cpp

Fit/Adapter/IFunctionAdapter.h

Fit/Adapter/Minuit2Minimizer.cpp

Fit/Adapter/Minuit2Minimizer.h

Fit/Adapter/ObjectiveFunctionAdapter.cpp

Fit/Adapter/ObjectiveFunctionAdapter.h

Fit/Adapter/ResidualFunctionAdapter.cpp

Fit/Adapter/ResidualFunctionAdapter.h

Fit/Adapter/RootMinimizerAdapter.cpp

Fit/Adapter/RootMinimizerAdapter.h

Fit/Adapter/RootResidualFunction.cpp

Fit/Adapter/RootResidualFunction.h

Fit/Adapter/RootScalarFunction.cpp

Fit/Adapter/RootScalarFunction.h