=str - #16048 - Switches to pattern-matching iso getOrElse to avoid allocation in ThunkTab and Flow.apply
+htp #15932 integrate SchemeDirectives from spray codebase
Merge pull request #15982 from bthuillier/release-2.3-dev

+htp #15932 Import SchemeDirectives from spray
Merge pull request #16059 from akka/wip-16048-avoid-thunks-√

=str - #16048 - Switches to pattern-matching iso getOrElse to avoid allo...
+str #16038 Create Source/Flow/Sink from partial flow graphs
Merge pull request #16061 from akka/wip-graphs-as-source-flow-sink-ban

+str #16038 Create Source/Flow/Sink from partial flow graphs
+str #15736 Initial version of JavaDSL for akka-streams (NOT complete)

Missing features are:
+ be able to use all junctions from Java
* re-think akka.stream.javadsl.japi (because variance)
+ better docs
+ enable all tests
+ Partial flow graph as well as GraphFlow tests