The ModuleTool uses a new class of connector called ModuleConnectionGraphicsItem. This connection always uses straight line and contains a merge-handle commmand inside. It does not have a handle.
The ModuleTool also uses a new PatGraphicsItem called ModuleLinkerItem. This item always belongs on the edge of its parentModule; this adjustment is made in the paint method. It is always an alias, so it hides itself when the original item is not present.