!htc Replace `Deferrable` with `FastFuture`
!htp,htk Upgrade from `Deferrable` to new `FastFuture`, closes #15962
Merge pull request #15975 from spray/wip-15962-mathias

 Remove `Deferrable[T]` and replace with POF (plain old Future)
+htp #15926 Import HostDirectives from spray
+hco #15945 Make Tcp and Http server binding closeable
Merge pull request #15983 from akka/wip-15945-unbind-tcp-and-http-connection-ban

+hco #15945 Make Tcp and Http server binding closeable
!str,hco #15945 Make creation of ServerBinding public again
=str #15900 Make fanout publisher actor name unique
=str #15892 Fix ClassCastException in ThunkSource

* and add test
Merge pull request #15986 from akka/wip-15945-clean-up-unbind-ban

!str,hco #15945 Make creation of ServerBinding public again
Merge pull request #15994 from akka/wip-15892-ClassCastException-ThunkSource-patriknw

=str #15892 Fix ClassCastException in ThunkSource
Merge pull request #15997 from akka/wip-15900-fanout-actor-name-patriknw

=str #15900 Make fanout publisher actor name unique
+str #15996 Add mapAsyncUnordered

* rename mapFuture to mapAsync
* add mapAsyncUnordered
* extract common things for emits to a trait
Merge pull request #15999 from akka/wip-15996-unordered-mapFuture-patriknw

+str #15996 Add unorderedMapAsync
+str #15960 Correction of FlowGraph variance
Merge pull request #16005 from akka/wip-15960-FlowGraph-variance-patriknw

+str #15960 Correction of FlowGraph variance
+str #15875 Hook-up unzip operation in the new Streams DSL

* handle output ports in FlowGraph
Merge pull request #16004 from akka/wip-15875-unzip-patriknw

+str #15875 Hook-up unzip operation in the new Streams DSL
=str #15960 Fix broken FlowGraphCompileSpec

* FlowGraphCompileSpec broke when merging in the unzip on top of
  the variance adjustements
* JunctionOutPort[T] must not be defined like JunctionOutPort[+T]
  because then the NextT = Nothing doesn't work
* Do we have a reason to use JunctionOutPort[+T]? I added +T
  only for symmetry reasons with JunctionInPort[-T].
Merge pull request #16008 from akka/wip-15960-variance-take2-patriknw

=str #15960 Fix broken FlowGraphCompileSpec