=pro #3833 Disable diagram verification for kernel and dataflow

* The problem was that those projects contain very few classes, without
  any diagrams, and therefore the scaladocVerifier fails
=clu,rem #3632 Correct wrong transport in docs
+act #3513 Clarify gracefulStop stopMessage, and add Java API
=doc #3102 Remove ComposableActor doc sample
=doc #3647 Clarify that existing FSM timer is canceled by setTimer
+sam #3607 Add maven pom.xml to akka-sample-main-java
=doc #3573 Clarify maxNrOfRetries in supervisor strategies
Merge pull request #1950 from akka/wip-3833-diagrams-check-patriknw

=pro #3833 Disable diagram verification for kernel and dataflow
Merge pull request #1951 from akka/wip-3632-doc-cluster-jmx-patriknw

=clu,rem #3632 Correct wrong transport in docs
Merge pull request #1952 from akka/wip-3513-doc-gracefulStop-custom-msg-patriknw

+act #3513 Clarify gracefulStop stopMessage, and add Java API
Merge pull request #1953 from akka/wip-3102-remove-ComposableActor-patriknw

=doc #3102 Remove ComposableActor doc sample
Merge pull request #1954 from akka/wip-3647-clarify-fsm-setTimer-patriknw

=doc #3647 Clarify that existing FSM timer is canceled by setTimer
Merge pull request #1955 from akka/wip-3573-doc-maxNrRestarts-patriknw

=doc #3573 Clarify maxNrOfRetries in supervisor strategies
Merge pull request #1956 from akka/wip-3607-mvn-pom-sample-patriknw

+sam #3607 Add maven pom.xml to akka-sample-main-java
Merge remote-tracking branch: upstream/master