Move away from JUL for logging and rely on slf4j
Ignore test relying on logs generated by JUL
Stop accepting new logs once the async connection is closed
Add guard to prevent recursive logging with log4j
Fix the condition to increase the waiting time
Do no add more logs when a lockdown is on.
Move to a stable version of jetty
Enable jetty tests only with java 7
Add plugins to the default build to avoid warnings

Even though the jetty plugin can't be used with java < 7 not providing
a version in those cases will generate warnings in the logs
Merge branch 'master' into raven-3.x

Conflicts:
	raven/src/main/java/net/kencochrane/raven/Raven.java
	raven/src/main/java/net/kencochrane/raven/marshaller/json/ExceptionInterfaceBinding.java