Dynamic Branches in default VaSet for all workspaces.

Automatically track Dynamic Branches for all VivWorkspaces.  and you get the svg and getSymboliksPaths patch for free!
should we just make the default _cb_dynamic_branch() handler just track dynamic branches, and leave any additional functionality to subclasses?  or do you like the "register new handlers" approach so that we don't have to subclass, we can make changes on the fly?