Add an extension point to define actions performed when timeout.
This generalizes 56c0e18c678f7ef912ceb0a78616128a209c19c5, and allow to add new actions as sending mails, executing commands.
Write regression tests for build-timeout plugin
Execute a command before timeout
Using build-timeout plugin to stop build but not force the build abort or failed
e-mail should be sent when the build is aborted
Notify but Don't Cancel a long running build