Fix NreplServer#isStarted
Fix MBean Registration.
1. The registration does no more happen automatically, but is manually requested.
2. There is a corresponding unregister method.
3. A unit test.
Put MBean Documentation in README
up the version of server example
Merge branch 'stanislas-master'
updated clojure version and set jvm-break SNAPSHOT as dependency of examples
added MBeanRegistration option on server creation. Fixed NreplServerSpring. Added test for server start/stop/registration.