GGEP-5 and GGEP-6

GGEP-5: add graphics editing plugin to gwt2 client. Also added class GeometryEditorFactory in editing plugin; this was incorrectly removed (don't know how).

GGEP-6: add graphics editing example jar to gwt2 client example. Had to change code in class AnnotatioContainer : method onViewPortChanged needs to be reviewed.
=> tested locally, example runs