ECLIPSE-1000 - Modified the JMX navigator OSGI facade to noy NPE given a...

... closed connector.

Modified the Camel fabric navigator to return an empty string given a lost Camel context Managed bean.
Modified the secure-shell view terminal disconnect method to check if it's already disconnected before
running the the super constructor.
Upgraded jbpm/drools target dependency to 6.0.0.Final