https://issues.jboss.org/browse/HORNETQ-1198 - fixing leaked threads
HORNETQ-1201 Avoid races resetting serverLocator0 and Activation.close(boolean).

Hopefully this will solve the intermittent failing tests due to
ClientSessionFactories left open.
Merge remote-tracking branch 'clebert/master-fix'

* clebert/master-fix:
  https://issues.jboss.org/browse/HORNETQ-1198 - fixing leaked threads