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
* and rename the factory for ActorPublisherSource,
from Source.apply to Source.actorPublisher
* including internal buffer, with OverflowStrategy
* support to complete/fail stream
* add supervion for stages and built in ops run by interpreter
* add supervision for mapAsync and mapAsyncUnordered
* add supervision to groupBy and splitWhen
* reference doc for scala and java
* remove isDemandAvailable
* hide emit from CompletionHandler context
* throw if more than one emit in response to an input
* had to remove the OrderedMerge test/sample because emitting
from CompletionHandler is currently not supported
* FlexiRoute and FlexiMerge might become more capable later, see issue 16753
* FlowMaterializer is now the actor independent interface
* ActorFlowMaterializer is the actor based interface
* MaterializerSettings renamed to ActorFlowMaterializerSettings
* impl.ActorBasedFlowMaterializer renamed to impl.ActorFlowMaterializerImpl
* Optimizations included in ActorFlowMaterializerSettings
* Note that http is using FlowMaterializer in api, but I suspect that it
will currently only run with a ActorFlowMaterializer
