+str #15588,#17229 Java 6 Synchronous File Sink / Source

These are synchronous implementations, because we need to be Java 6
  compatible while developing on 2.3.x. However asynchronous
  implementations using AsynchronousFileChannel will come soon for JDK7
  users.

+ ActorPublisher/Subscriber now manage stopping of the actor
+ added documentation on configuring dispatcher for File IO
+ properly handle if source file does not exist
+ file sink / source come with default io dispatcher
> verified no actors are leaking
> exceptions are caught and onErrored properly
+ moved files to akka.stream.io
+ Added OutputStreamSink and InputStreamSource

akka-docs-dev/rst/scala/code/docs/stream/io/StreamFileDocSpec.scala

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2015 Typesafe Inc. <http://www.typesafe.com>
+ */
+package docs.stream.io
+
+import java.io.File
+
+import akka.stream._
+import akka.stream.io.SynchronousFileSource
+import akka.stream.io.SynchronousFileSink
+import akka.stream.testkit.AkkaSpec
+import akka.stream.testkit.StreamTestKit
+import akka.util.ByteString
+
+class StreamFileDocSpec extends AkkaSpec(StreamTestKit.UnboundedMailboxConfig) {
+
+  implicit val ec = system.dispatcher
+  implicit val mat = ActorFlowMaterializer()
+
+  // silence sysout
+  def println(s: String) = ()
+
+  val file = File.createTempFile(getClass.getName, ".tmp")
+
+  override def afterTermination() = file.delete()
+
+  {
+    //#file-source
+    import akka.stream.io._
+    //#file-source
+  }
+
+  {
+    //#file-source
+    val file = new File("example.csv")
+    //#file-source
+  }
+
+  "read data from a file" in {
+    //#file-source
+    def handle(b: ByteString): Unit //#file-source
+    = ()
+
+    //#file-source
+
+    SynchronousFileSource(file)
+      .runForeach((chunk: ByteString) ⇒ handle(chunk))
+    //#file-source
+  }
+
+  "configure dispatcher in code" in {
+    //#custom-dispatcher-code
+    SynchronousFileSink(file)
+      .withAttributes(ActorOperationAttributes.dispatcher("custom-file-io-dispatcher"))
+    //#custom-dispatcher-code
+  }
+}