Test returning a nomatch on interrupt

since we already get an AMI Event for Hangup, hopefully not throwing an uncaught exception here allows the call to complete gracefully and correctly, an lets us handle post-hangup stuff
Clean this code up a wee bit
Update changelog
Merge pull request #14 from runningferret/feature/handle_interrupted_recog

Feature/handle interrupted recog
add dtmf-term-timeout
update CHANGELOG