PostgreSQL backend is not implemented in Havana

It will come back in icehouse, or perhaps when patches are backported
sooner in havana,but at the moment the option doesn't make any sense.
Do not refer to Ceilometer as OpenStack Telemetry

http://lists.openstack.org/pipermail/openstack-dev/2014-February/026323.html
Merge pull request #73 from dirkmueller/release/roxy/master

PostgreSQL backend is not implemented in Havana
Merge pull request #74 from vuntz/naming

Do not refer to Ceilometer as OpenStack Telemetry