ws: disable perMessageDeflate

per-message deflate could be useful for some of our messages, and it is
even enabled by default, but it is also a little bit buggy, so we
disable it so we don't end up with 'write after end' errors from the
underlying socket.

This is most certainly a bug in WS.

lib/ws-channel.js

@@ -68,8 +68,15 @@ WebsocketChannel.prototype.connect = function(uri, _token) {
   this._uri = uri;
   this._token = token;
 
-  var headers = {'x-mesh-token': token};
-  var websocket = new Websocket(uri, {headers: headers});
+  var opts = {
+    headers: {'x-mesh-token': token},
+    // TODO: per-message deflate could be useful for some of our messages, and
+    // it is even enabled by default, but it is also a little bit buggy, so we
+    // disable it so we don't end up with 'write after end' errors from the
+    // underlying socket.
+    perMessageDeflate: false,
+  };
+  var websocket = new Websocket(uri, opts);
 
   this._attach(websocket);