remove not used connector classes

src/cpu/VirtualFluids.h

.../VirtualFluidsCore/Connectors/Block3DConnectorFactory.cpp

...pu/VirtualFluidsCore/Connectors/Block3DConnectorFactory.h

...ualFluidsCore/Connectors/CoarseToFineBlock3DConnector.cpp

...rtualFluidsCore/Connectors/CoarseToFineBlock3DConnector.h

...dsCore/Connectors/CoarseToFineNodeSetBlock3DConnector.cpp

...uidsCore/Connectors/CoarseToFineNodeSetBlock3DConnector.h

src/cpu/VirtualFluidsCore/Connectors/ConnectorFactory.h

...rtualFluidsCore/Connectors/D3Q27ETOffConnectorFactory.cpp

...VirtualFluidsCore/Connectors/D3Q27ETOffConnectorFactory.h

...ualFluidsCore/Connectors/FineToCoarseBlock3DConnector.cpp

...rtualFluidsCore/Connectors/FineToCoarseBlock3DConnector.h

...dsCore/Connectors/FineToCoarseNodeSetBlock3DConnector.cpp

...uidsCore/Connectors/FineToCoarseNodeSetBlock3DConnector.h

src/cpu/VirtualFluidsCore/Visitors/ConnectorBlockVisitor.cpp

src/cpu/VirtualFluidsCore/Visitors/ConnectorBlockVisitor.h