=clu #3517 Guard against wrong random selection

* When all weights in the map are zero total became 0, which is not
  valid in random pick. Treat this special case as empty WeightedRoutees, i.e.
  no availble targets and routing to deadLetters.
=clu #3546 Change log level of gossip from unknown

* It is pretty normal when joining so users should not be worried
* Change to debug level
=clu #3536 Update doc of hostname port params in cluster jmx script

* This was changed in the switch to jmxsh (72aa5ef), but since
  we released with space separator I updated the documentation to that
  format.
!act #3526 Make SupervisorStrategy.logFailure public

* This change is not source compatible since anyone that has
  overridden logFailure will have compilation error
  "has weaker access privileges; it should be public"
=pro #3552 Upgrade ScalaTest to 1.9.2-SNAP2 for dbuild

* This can't go into 2.2.x since ScalaTest 1.9.2-SNAP2 has source incompatible changes and the dependecy in akka-multi-node-node-testkit would force people to upgrade.
Merge pull request #1645 from akka/wip-3517-AdaptiveLoadBalancingRouter-off-by-one-patriknw

=clu #3517 Guard against wrong random selection
Merge pull request #1646 from akka/wip-3546-ignore-gossip-loglevel-patriknw

=clu #3546 Change log level of gossip from unknown
Merge pull request #1647 from akka/wip-3536-cluster-jmx-script-patriknw

=clu #3536 Update doc of hostname port params in cluster jmx script
Merge pull request #1648 from akka/wip-3526-public-log-failure-patriknw

!act #3526 Make SupervisorStrategy.logFailure public
Merge pull request #1650 from akka/wip-3552-upgrade-scalatest-for-dbuild-ban

=pro #3552 Upgrade ScalaTest to 1.9.2-SNAP2 for dbuild
Merge remote-tracking branch: upstream/master