QmlDesigner: Update AnchorIndicatorGraphicsItem after updating anchorlines

Change-Id: Ibdde4d8a32abac8bc7b1572507c7a8094d28f604
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
QmlDesigner: Add BindingIndicator

Change-Id: I46a763f87e19114e223b9eb897cbb89cf1f4c3d5
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>