DeleteRoute implementation

[kevinburke1]

Looking at the Client API and codebase, it is possible to add a route with a callback, but impossible to delete a route. The code is there - deleteRoute in router.go and it's called from Unsubscribe but there's no way to get at it from the public API.

[t2wu]

Found any solution to this yet? I was looking at it as an alternative to subscribe a one callback if I intend to bind two callbacks per topic.

[MattBrittan]

I've added a help wanted tag to this; it should be a simple change (but care is needed to ensure its threadsafe).