Fix singleton function to have multiple in memory

orangecontrib/tomwer/widgets/FtseriesWidget.py

orangecontrib/tomwer/widgets/test/test_darkref.py

orangecontrib/tomwer/widgets/test/test_ftseries.py

tomwer/core/DarkRefs.py

tomwer/core/FolderTransfert.py

tomwer/core/RSyncManager.py

tomwer/core/ReconsParams.py

tomwer/core/ftseries/Ftseries.py

tomwer/core/qtApplicationManager.py

tomwer/core/test/test_rsyncmanager.py

tomwer/core/tomodir/_TomoDirProcess.py

tomwer/core/utils/Singleton.py

tomwer/core/utils/benchmark.py

tomwer/gui/DarkRefWidget.py

tomwer/gui/FtseriesMixIn.py

tomwer/gui/H5StructsEditor.py

tomwer/gui/reconsParamsEditor/PaganinWidget.py

tomwer/gui/reconsParamsEditor/__init__.py

tomwer/gui/test/test_recPyHSTWidget.py

tomwer/simpleworkflow/test/test_core_process_loading.py