longer default timeout for mongodb

The default systemd TimeoutStartSec of 30 seconds isn't long enough on
slow systems.  Make it 240 seconds so we don't timeout (mainly an
issue the first time mongodb is started).
Merge pull request #418 from cwolferh/mongodb_timeout

longer default timeout for mongodb
BZ #1173217 - Errors in /var/log/ceilometer/collector.log.

https://bugzilla.redhat.com/show_bug.cgi?id=1173217

The rabbit host/hosts values were being incorrectly set, causing ceilometer to
attempt to call rabbit on the incorrect IP.
Merge pull request #424 from jguiditta/BZ1173217-ceilo-rabbit-fix

BZ #1173217 - Errors in /var/log/ceilometer/collector.log.