adding ReliableDelivery support; marking internal classes as internal
started integrating reliable delivery into the AkkaPduCodec
implementing RemoteDeliverySupervisor
added stubs for AddressTerminated, finished ReliableDeliverySupervisor
starting work on EndpointWriter; need to implement stash
added basic stash capabilities
completed EndpointWriter
finished all endpoint actors
updated supervisor strategy for RemoteEndpointManager
Merge pull request #114 from Aaronontheweb/remote-fixes

[Unstable] ReliableDeliverySupervisor, RemoteWriter, RemoteReader, Stash support