Add extended logging options.

There is a range of extended logging options in Openstack services that use
openstack.common.logger (Ceilometer, Cinder, Heat, Keystone, Nova). Adding
ceilometer::logging to support them.

No blueprint/spec, as discussed in the IRC meeting on 08-11-2014.

Change-Id: I910e2f9e4f3ad1991d58ba6df16adfbc85e20131