* stream overloads of accept which take both a message
and a buffer sequence are removed.
Actions Required:
* Do not call websocket accept overloads which take
both a message and a buffer sequence, as it is
illegal per rfc6455.
fix#642
* Calls to stream::close and stream::async_close will
automatically perform the required read operations
Actions Required:
* Remove calling code which drains the connection after
calling stream::close or stream::async_close