Do not try to generate ScalaDoc diagrams for akka-channels-tests since it will contain none. See #3010
Preserve sender when sending to deadLetters, see #3009
zeromq socket pinned to the thread that created it, see #2863
Rename event-handlers to loggers, see #2979

* Rename config akka.event-handlers to akka.loggers
* Rename config akka.event-handler-startup-timeout to
  akka.logger-startup-timeout
* Rename JulEventHandler to JavaLogger
* Rename Slf4jEventHandler to Slf4jLogger
* Change all places in tests and docs
* Deprecation, old still works, but with warnings
* Migration guide
* Test for the deprecated event-handler config
Merge pull request #1102 from akka/wip-2979-loggers-patriknw

Rename event-handlers to loggers, see #2979
Merge pull request #1106 from akka/wip-2863-zeromq-pinned-patriknw

zeromq socket pinned to the thread that created it, see #2863
Merge pull request #1105 from akka/wip-3009-deadLetters-sender-patriknw

Preserve sender when sending to deadLetters, see #3009
Merge git://github.com/akka/akka