Fix naming inconsistency for db password databag

The other openstack services cookbooks refer to the db password databag by the
service name (nova, swift, quantum) and therefore openstack-metering cookbook
should call the db password databag by service name 'ceilometer' to make it
consistent

Change-Id: I0a17e065f630f8506a5dd94b3a1ff8ed44482adc
Add optional host to ceilometer.conf

By default cfg.CONF.host is the `hostname` of local node, however, not all envs
register their hosts by the fqdn.  This allows a configurable attr to add to
the ceilometer.conf

Change-Id: If80cd5264a02eeb7c94655716839642dd7993906
Add debug option

Change-Id: I5523a241975097510b29cbf58df59992db7b9411
Temporary fix agent-compute dpkg bug 1221945

See https://bugs.launchpad.net/cloud-archive/+bug/1221945
The ubuntu cloud archive ceilometer-agent-compute pkg has a bug in which init
script isn't installing properly gets installed as:
/etc/init/ceilometer-agent.conf.dpk-new therefore until it gets fixed this temp
solution works

Change-Id: I0f017c834e23fb731e5ca57fb9ab90826072c1cd