Merge pull request #1652 from minrk/zmqcompat

add patch_pyzmq() for backporting a few changes from newer pyzmq

* fixes missing constants in super-old pyzmq
* define ioloop.install if not defined
* never allow jsonlib to be used by zmq.utils.jsonapi (#1520).

Closes #1520.

IPython/frontend/html/notebook/notebookapp.py

@@ -35,13 +35,7 @@ import zmq
 # Install the pyzmq ioloop. This has to be done before anything else from
 # tornado is imported.
 from zmq.eventloop import ioloop
-# FIXME: ioloop.install is new in pyzmq-2.1.7, so remove this conditional
-# when pyzmq dependency is updated beyond that.
-if hasattr(ioloop, 'install'):
-    ioloop.install()
-else:
-    import tornado.ioloop
-    tornado.ioloop.IOLoop = ioloop.IOLoop
+ioloop.install()
 
 from tornado import httpserver
 from tornado import web