Refactor header status, reason, and target (API Change):

* header::result is a family of functions to replace header::status

* header interface now uses status enum and also ints

* reason-phrase is no longer stored unless the user explicitly
  requests it.

* When serializing, the standard reason is used for the
  corresponding status code unless the user has changed it.

include/beast/websocket/impl/accept.ipp

@@ -148,7 +148,8 @@ operator()(error_code ec, bool again)
         // sent response
         case 1:
             d.state = 99;
-            if(d.res.status != 101)
+            if(d.res.result() !=
+                    http::status::switching_protocols)
                 ec = error::handshake_failed;
             if(! ec)
             {