-str - Improvements and renames in internal streams classes

* Renames Module.grow -> Module.compose
 * Renames Module.connect -> Module.wire
 * Renames Module.growConnect -> Module.fuse
 * Renames Module.wrap -> Module.nest

 * Adds explicit identity equals and hashCode to InPort and OutPort

 * Reimplements many of the Source factories to avoid copying

 * Documents Module.compose, Module.fuse, Module.wire and Module.nest

 * Removes Attributes.nameLifted

 * Optimizes Attributes.nameOrDefault

akka-stream/src/main/scala/akka/stream/impl/io/IOSources.scala

@@ -20,6 +20,7 @@ import scala.concurrent.{ Future, Promise }
 private[akka] final class SynchronousFileSource(f: File, chunkSize: Int, val attributes: Attributes, shape: SourceShape[ByteString])
   extends SourceModule[ByteString, Future[Long]](shape) {
   override def create(context: MaterializationContext) = {
+    // FIXME rewrite to be based on AsyncStage rather than dangerous downcasts
     val mat = ActorMaterializer.downcast(context.materializer)
     val settings = mat.effectiveSettings(context.effectiveAttributes)