Ensure swift-container-sync service is enabled

* The ubuntu cloud packages are missing an upstart config
and /etc/init.d wrapper for the swift-container-sync service.
This adds them if missing on the ubuntu platform so that we can
start this service successfully.
* Ensure the swift-container-sync is enabled and running
when allowed_sync_hosts is defined
* Swauth requires its own separate declaration of
allowed_sync_hosts in the proxy configuration as well

Change-Id: I638d43445edfd1f9519911212942ac8d69d4fff2