Unique ids for transitions

Transitions currently do not specify the presence of an id="..." attribute. As any pair of states can have n transitions anchored at both ends, even with the same event(s), the only way to uniquely talk about a particular transition (to any sort of an external system) is to fully describe it. Contrast this with a state, which can be uniquely identified with a short id string.

This causes no problem for the runtime itself. However, for external tools working with an SCXML document this can be annoying. I'm thinking specifically of a visual runtime debugger for a state machine. For example, consider the scxmlgui tool[1]. It has a simple network protocol for highlighting/unhighlighting either states or transitions. The states are referred to by id. The transitions are referred to by source/target state ids, which clearly does not uniquely reference a specific transition in all cases.

It will be trivial to add a namespaced attribute to transitions to track this, but I would feel cleaner if this were in the spec itself. Any chance of having an a non-required id (ID) attribute spec'd on <transition> elements?

[1] https://code.google.com/p/scxmlgui/