Merge branch 'FitWidget2' into develop

Core/Algorithms/src/ProgressHandler.cpp

Fit/FitKernel/inc/FitKernel.h

Fit/FitKernel/inc/FitSuite.h

Fit/FitKernel/src/FitKernel.cpp

Fit/FitKernel/src/FitSuite.cpp

Fit/FitKernel/src/FitSuiteFunctions.cpp

Fit/PythonAPI/src/FitSuite.pypp.cpp

GUI/coregui/Models/FitModel.cpp

GUI/coregui/Models/FitModel.h

GUI/coregui/Models/FitParameterItems.cpp

GUI/coregui/Models/FitParameterItems.h

GUI/coregui/Models/FitParameterModel.cpp

GUI/coregui/Models/FitParameterModel.h

GUI/coregui/Models/FitProxyModel.cpp

GUI/coregui/Models/FitSelectorModel.cpp

GUI/coregui/Models/FitSelectorModel.h

GUI/coregui/Models/ItemFactory.cpp

GUI/coregui/Models/ParameterModelBuilder.h

GUI/coregui/Models/ParameterizedItem.cpp

GUI/coregui/Models/ParameterizedItem.h