remove redundant object creation in log
improve shut down strategies when debugging launched nexus bundles

Previous to this change, if bundle was suspended for debugging and start timeout was exceeded, test would end and leave suspended bundle running.

Now in the suspended state and start timeout expiration, we resume the suspended JVM and then immediately halt it using command monitor

Other other available methods of shutting down suspended jvm are unreliable - JSW always would try to restart instead of shutdown.

Made logging messages more suitable for tracking multiple nexuses under test also in this commit while testing these changes.