Fix in fitting (chi2 normalization),  small refactoring and code cleanup in fitSuite and fit observers.

Conflicts:
	App/src/TestDetectorResolution.cpp
	App/src/TestFittingModule.cpp
	App/src/TestIsGISAXS1.cpp
	App/src/TestIsGISAXS10.cpp
	App/src/TestIsGISAXS11.cpp
	App/src/TestMultiLayerRoughness.cpp
	App/src/TestPerformance.cpp
	App/src/TestRootTree.cpp
	Core/Algorithms/inc/Experiment.h
	Core/Algorithms/src/Experiment.cpp
	Core/PythonAPI/src/PythonInterface_classes_2.cpp

Restructure global data shared by App and Core: command line options are now passed as objects instead of accessed through a singleton

Conflicts:
	App/src/TestMesoCrystal1.cpp