Fix server "Bad file descriptor" error under gevent 1.1, Lawouach#170

In gevent 1.1, underlying socket is closed when WSGI handler returns, so we need to keep WSGI handler runing until websocket handler returns.

gevent/gevent#633

ws4py/server/geventserver.py

@@ -54,7 +54,11 @@ def run_application(self):
 
             ws = self.environ.pop('ws4py.websocket', None)
             if ws:
-                self.server.pool.track(ws)
+                ws_greenlet = self.server.pool.track(ws)
+                # issue #170
+                # in gevent 1.1 socket will be closed once application returns
+                # so let's wait for websocket handler to finish
+                ws_greenlet.join()
         else:
             gevent.pywsgi.WSGIHandler.run_application(self)