Improve support for writing binray data

In order to write binary data with q-io, the data must be either a string or a Buffer. However, when using q-io via q-connect over a websocket, you cannot send the data as string without having some conversion done. As Buffer is not exposed on the client side, the best way is to send it as a Bytes array.

This patch allow you to write binary data which is send as an array (or any other type the Buffer constructor support)

Note: This patch does not address any similar potential issue with reading binary data which need to be send back to the client via websocket.