WebSocket optimizations (API Change):

The websocket stream is optimized to contain a small
circular static buffer, reducing the number of I/O calls when
reading data. The size of the buffer is tuned for maximum
performance with TCP/IP and no long needs configuration:

* read_some replaces read_frame
* write_some replaces write_Frame
* async_read_some replaces async_read_frame
* async_write_some replaces async_write_frame

* websocket::stream::read_buffer_size is removed

Actions Required:

* Remove calls websocket::stream::read_buffer_size

* Use read_some and write_some instead of read_frame and write_frame

doc/qbk/08_design/3_websocket_zaphoyd.qbk

@@ -328,7 +328,7 @@ without bringing it all into memory.
         [```
             template<class ConstBufferSequence>
             void
-            write_frame(bool fin,
+            write_some(bool fin,
                 ConstBufferSequence const& buffers);
         ```]
         [