Add client timeout to metadata hanging request

This ensures we don't hang even if the metadata server
does not honor the timeout we pass it. We don't need
to handle the exception as the daemon loop catches and
retries on all exceptions.
Adjust timeout on hanging metadata request

* Tell urllib2 to wait a little longer than the timeout
  we gave to metadata server.
* Reduce timeout from 5mins to 1min.
Merge pull request #94 from davidn/patch-1

Add client timeout to metadata hanging request