Allow use of ${} style expressions in defining the build timeouts
fix build failure
fix tests
Fix unit tests and add note [FIXED JENKINS-9457] [FIXED JENKINS-19773] [FIXED JENKINS-20526]
Merge pull request #29 from stephenc/expression-support

Allow use of ${} style expressions in defining the build timeouts

Conflicts:
	src/main/java/hudson/plugins/build_timeout/BuildTimeOutStrategy.java