DiSLServer: cleaned up error handling and reporting.
DiSLServer: support for indicating server readiness and shutdown.
DiSLServer: moved to Executor framework for thread management.
DiSLServer: collect timing information for communication and request processing.
DiSLServer, MesageChannel: switch to channel-based buffered I/O.
Worker: moved connection handling to DiSLServer.ConnectionHandler.
Worker: cleaned up and renamed to RequestProcessor.