* Re enabling Java tests in akka-docs (they were not run before)
* Fixed bug #19764
* #19735 Rewrote every sample using the deprecated PushPullStage and friends
using GraphStage
* Pruned old unused graph images
* Added missing graffle file for new graph images
* Sink.seq (Scala DSL) now returns immutable.Seq rather than Seq
* Sink.seq will not silently truncate when incoming elements is > Int.MAX_VALUE
* minor doc fixes
* replacing various grouped(n) / Sink.head with limit(n) / Sink.seq in various tests
* fix inconsistent indentation in RequestParserSpec
This entails:
* adding akka.pattern.PatternCS.* to enable ask etc. with
CompletionStage
* changing RequestContext to offer an ExecutionContextExecutor for the
CompletionStage.*Async combinators
* splitting up akka.stream.Queue for JavaDSL consistency
Any previous usage can be represented in this fashion while typically
saving one function allocation and also saving the function literal’s
syntax overhead (for the seed). Plus a new feature: the provided
iterator does not have to be infinite, limiting how far expand is
allowed to go.
