akka/akka — pull request #16092 by bantonsson (2014-10-14 07:22:03+00:00)
Title: (Only for review) !str Hide Tap and Drain from common APIs

* Introduce SimpleSource and KeyedSource traits
* Create Source/Sink helpers to create all Taps/Drains
* Make concrete Tap/Drain implementations private[scaladsl2]