Merge branch 'platon' into develop

Core/FormFactors/FormFactorPolyhedron.cpp

Core/PythonAPI/libBornAgainCore.py

Core/PythonAPI/libBornAgainCore_wrap.cxx

Core/PythonAPI/libBornAgainCore_wrap.h

Core/Tools/PyGenVisitor.cpp

Fit/PythonAPI/libBornAgainFit.py

Fit/PythonAPI/libBornAgainFit_wrap.cxx

Fit/PythonAPI/libBornAgainFit_wrap.h

GUI/coregui/Models/FormFactorItems.cpp

GUI/coregui/Models/FormFactorItems.h

GUI/coregui/Models/GUIObjectBuilder.cpp

GUI/coregui/Models/GUIObjectBuilder.h

GUI/coregui/Models/GroupPropertyRegistry.cpp

GUI/coregui/Models/ItemFactory.cpp

GUI/coregui/Models/item_constants.h

GUI/coregui/Views/SampleDesigner/SampleDesigner.qrc

...oregui/Views/SampleDesigner/images/ff_AnisoPyramid_64.png

GUI/coregui/Views/SampleDesigner/images/ff_Box_64.png

GUI/coregui/Views/SampleDesigner/images/ff_Cone6_64.png

GUI/coregui/Views/SampleDesigner/images/ff_Cone_64.png