do not close over context.self in TickGenerator, see #3393
FIXME in cluster, see #3192
Remove redundant should/must in tests, see #3272
fix some FIXMEs, see #3192

- remove some outdated ones (which were already fixed but not removed)
- make socket options fully configurable in NettyTransport
- also apply socket options to outbound connections, not only the listen
  socket
- remove timeout from taking the lock in RepointableActorRef, because we
  cannot afford to lose system messages anymore, so we should rather
  block the sender
Split mailbox documentation into a separate section. See #3341
=== was not testing what it thought it did
Getting started link to Activator
 #3335 - Adding connection timeout to TCP connections
Merge pull request #1481 from akka/wip-3341-split-out-mailbox-documentation-ban

Split mailbox documentation into a separate section #3341
remove fallback to default-dispatcher, see #3394
Merge pull request #1488 from akka/wip-3393-Trigger-NPE-∂π

do not close over context.self in TickGenerator, see #3393
Merge pull request #1484 from akka/wip-3192-FIXMEs-∂π

fix some FIXMEs, see #3192
Disable cluster stats by default, see #3348

* Add VectorClockStats
Merge pull request #1486 from akka/wip-3348-ClusterStats-patriknw

Disable cluster stats by default, see #3348
Merge pull request #1489 from akka/wip-3192-fixme-patriknw

FIXME in cluster, see #3192
Merge pull request #1491 from akka/wip-3272-must-should-patriknw

Remove redundant should/must in tests, see #3272
Merge pull request #1492 from akka/wip-getting-started-patriknw

Getting started link to Activator
Mark not impl parts in Cluster Specification, see #3331
Warn about -optimize flag, see #3233
 #3405 - fix race between consumer and producer for MPSC