Ability to stop (cancel) an Originate

[bklang]

I need the ability to stop a dial that is in progress, before the timer on the dial expires.

[benlangfeld]

So since a SIP 100 will trigger a response to a dial, and the 100 should come super fast, an ability to cancel a <dial/> is only useful in failure scenarios. I've not seen any real-world complaints about this so far, so I'm leave this alone for now.