#3272: Eliminate redundant 'should' in DataflowSpec test
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Publish cluster metrics periodically, see #3296

* instead of when it receives metrics gossip and when it collects metrics
Upgrade ScalaBuff to 1.2.0
Merge pull request #1435 from akka/wip-upgrade-scalabuff-to-1.2.0-ban

Upgrade ScalaBuff to 1.2.0
Heartbeat interval was too low compared to awaitCond sampling #3289
io-tests: simplify TcpConnectionSpec in preparation for coming modifications

This doesn't change any test logic, it merely structures the test fixture code a bit differently to make it easier to insert additional mocks required for coming additions.
io: small clean-ups
io: remove SelectionKey lookup and reduce IO-layer-internal message volume
io: add comments based on review feedback
Merge pull request #1420 from akka/wip-3296-pub-metrics-patriknw

Publish cluster metrics periodically, see #3296
Connection retries to shutdown node, see #3326

* In EC2 connection time out is around 1 minute. A few messages
  were sent after quarantining and these caused endless restarts,
  and connect attempts with 1 minute interval.
* This change makes sure that the endpoint is stopped after the first
  failed connection attempt.
* Changed default settings for netty connection-timeout, and matching
  retry window to allow for 3 restarts
Forward port of release and build changes from 2.1
Merge pull request #1424 from akka/wip-3326-connection-retries-patriknw

Connection retries to shutdown node, see #3326
Compression of large cluster messages, see #3355
make release script really clean out the working directory
fix release printed in docs header
Merge pull request #1438 from drewhk/wip-release-script-updates-drewhk

Forward port of release and build changes from 2.1