*************************************************************************** attachables.t

This module forms part of the adv3Lite library (c) 2012-13 Eric Eve

The attachables file provides a framework for simple and common case attachables.

It treats attachment as an asymmetric relationship. ATTACH A TO B is not the same as ATTACH B TO A. It also treats it as a many-to-one relationship: the object that is attached can only be attached to one object at a time, but the object it's attached to can have multiple objects attached to it.