* Removes `Synchronous` from the names and descriptions of File I/O as it leaks impl details
* Removes the factries for FileSource and FileSink and puts them in Source and Sink respectively
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
