A wrapper for $(D_PSYMBOL createConnection()) returning a (reader, writer) pair.
The reader returned is a $(D_PSYMBOL StreamReader) instance; the writer is a $(D_PSYMBOL StreamWriter) instance.
The arguments are all the usual arguments to $(D_PSYMBOL createConnection()) except protocolFactory; most common are host and port, with various optional arguments following.
Additional arguments are $(D_PSYMBOL eventLoop) (to set the event loop instance to use) and $(D_PSYMBOL limit) (to set the buffer limit passed to the $(D_PSYMBOL StreamReader)).
(If you want to customize the $(D_PSYMBOL StreamReader) and/or $(D_PSYMBOL StreamReaderProtocol) classes, just copy the code -- there's really nothing special here except some convenience.)