ISPN-4225 Upgrade to JGroups 3.5.0.Beta5
ISPN-4190 Use Message.Flag.DONT_LOOPBACK instead of RequestOptions.setExclusionList

DONT_LOOPBACK is now a transient flag
ISPN-3743

Ignore some of the errors that can be thrown by a node while stopping:
IllegalStateException and NullPointerException.