Enables and manages relocation of either end of an IDiagramConnection and the DiagramConnectionElement that graphically represents it. That is, this thumb modifies either the ToConnectionPoint or the FromConnectionPoint properties of the connection that this thumb is assigned to.

The position of the end of the connection being relocated is dynamically changed as the mouse is dragged allowing for a rubberbanding effect. This thumb can relocate either the 'to' or 'from' connection point to another connection point mounted on either an IDiagramNode or an IDiagramConnection that the mouse is over when released. If the mouse is released over nothing, then the connection being relocated is put back to its original connection points.