reviewed portion of tooling.base.ui

...e/ui/dnd/gef/ConnectionCompositionDropTargetListener.java

...ortiss/tooling/base/ui/dnd/gef/ConnectionDragContext.java

...ortiss/tooling/base/ui/dnd/gef/ConnectionDropContext.java

...base/ui/dnd/gef/ElementCompositionDropTargetListener.java

...g/fortiss/tooling/base/ui/dnd/gef/ElementDropContext.java

...ase/ui/dnd/jface/ViewerElementCompositionDropAdapter.java

...org/fortiss/tooling/base/ui/editor/DiagramEditorBase.java

...c/org/fortiss/tooling/base/ui/editor/FormsEditorBase.java

...src/org/fortiss/tooling/base/ui/editor/GEFEditorBase.java