+act Add japi.Pair and japi.Predicate for streams
Merge pull request #15196 from akka/wip-stream-japi-patriknw

+act Add japi.Pair and japi.Predicate for streams
=act Add @SerialVersionUID to japi.Pair
Merge pull request #15201 from akka/wip-pair-serialversionuid-patriknw

=act Add @SerialVersionUID to japi.Pair
=act Add `putByteArrayUnsafe` optimization to `ByteStringBuilder`
=doc #15234 add new google analytics tracker
=pro #15116 Update Typesafe Config to 1.2.1
Merge pull request #15235 from 2m/new-google-analytics

=doc #15234 add new google analytics tracker
Merge pull request #15238 from akka/wip-15166-config-1.2.1-ban

=pro #15116 Update Typesafe Config to 1.2.1
Merge pull request #15233 from akka/wip-15232-putByteArrayUnsafe-ban

=act Add `putByteArrayUnsafe` optimization to `ByteStringBuilder`
+con #15157 Changed ClusterSharding.start to return the shardRegion
ActorRef #15209

* Changed ClusterSharding.start to return the ActorRef to the shardRegion (#15157)

* Fixed indentation, and removed unused import

* Test for new API
* removed unused import

- Moved barrier outside of the runon

(cherry picked from commit 619585c50e5801c1b79a39df6df770545cf9fbf4)
Merge pull request #15254 from akka/wip-15157-clustersharding-start-API-backport-patriknw

+con #15157 Changed ClusterSharding.start to return the shardRegion (for validation)
=act #15265 Make TcpConnection handle Suspend/ResumeReading while waiting for Register
Merge pull request #15277 from akka/wip-15265-FAILED-PullReadingSpec-ban

=act #15265 Make TcpConnection handle Suspend/ResumeReading while waiting for Register
=per #15280 Make snapshot header length field deserialize correctly
=pro #15290 Make validatePullRequest run all tests
Merge pull request #15296 from akka/wip-15290-validatePullRequest-runs-test-2.3-ban

=pro #15290 Make validatePullRequest run all tests
Merge pull request #15287 from akka/wip-15280-snapshot-serialization-problem-ban

=per #15280 Make snapshot header length field deserialize correctly
+str #15174 Add dispatcher setting to FlowMaterializer

* Verify dispatcher with custom default mailbox
+str #15172 Add javadsl.Duct as free-standing Flow

* foreach Void