Several changes:

- Changed to listen for build completion messages instead of requiring polling (uses https://wiki.jenkins-ci.org/display/JENKINS/Notification+Plugin)
- Retrieve and say branch name from git builds (probably breaks for non-git)
- Retrieve error information and say the first one (requires an artifact with a list of errors)
- Say build finished notifications similar to the style of the Jenkins IRC plugin
- some silly nonsense for fun.