Update use of ceilometer puppet classes

This patch updates the ceilometer_controller.pp and compute_common.pp
to work with updated ceilometer puppet module. These manifests now
use the ceilometer::agents::auth class to setup authentication and the
the ceilometer::agents::central and ceilometer::agents::compute
classes to enable the agents.
Merge pull request #74 from rohara/master

Update use of ceilometer puppet classes