added edit policies and gef command stack support

...c/org/fortiss/tooling/base/command/ConnectionCommand.java

...unk/src/org/fortiss/tooling/base/connect/DragContext.java

...se/editpart/policy/ConnectionGraphicalNodeEditPolicy.java

...ss/tooling/base/editpart/policy/LayoutEditPolicyBase.java

...ortiss/tooling/base/editpart/policy/RemoveEditPolicy.java

...fortiss/tooling/base/internal/command/EMF2GEFCommand.java

...fortiss/tooling/base/internal/command/GEF2EMFCommand.java

...ss/tooling/base/internal/command/GEF2EMFCommandStack.java