Collect and consolidate the various timers in the app.

Poll period when xmpp is working, and when it is not, plus
the keepalive ping time.
Raise keepalive period from 1 to 10 minutes.

Research suggests that 1-2 hours is fast enough.
Increase printer poll to 1/hr when XMPP working.
Variable spelling errors in xmpp.py exception handling.

Missing 'n' in XmppConnection self._conected.
Unhandled exception in XMPP recv.

The following was in the user.log.

Traceback (most recent call last):
012  File "/usr/share/cloudprint/cloudprint/cloudprint.py", line 373, in process_jobs
012    xmpp_conn.await_notification(sleeptime)
012  File "/usr/share/cloudprint/cloudprint/xmpp.py", line 189, in await_notification
012    self._read_socket()
012  File "/usr/share/cloudprint/cloudprint/xmpp.py", line 55, in _read_socket
012    data = self._wrappedsock.recv(1024)
012  File "/usr/lib/python2.7/ssl.py", line 305, in recv
012    return self.read(buflen)
012  File "/usr/lib/python2.7/ssl.py", line 224, in read
012    return self._sslobj.read(len)
012error: [Errno 104] Connection reset by peer

Assume that this is because the exception is not of type 'Exception',
and change the except in process_jobs to pure except:.