title: gevent.Timeout not raised
body: <p>I have a server that does "some stuff" in a section and I have a "with gevent.Timeout(5)" around that. I have some checks going on in another greenlet and through that I noticed that one of the greenlets which did that "some stuff" was running for 45mins. I had to eventually restart the program to kill it (I know of other ways of killing it but that's not the problem..). </p>
  
  <p>I monkey patching using gevent.monkey.patch_all() as well. The "some stuff" part does involve network connections and I am guessing something got stuck in one of those places. I don't understand why the timeout exception was not raised. Does anyone have any idea why the gevent.Timeout exception might not have been raised? </p>