Ceilometer integration

  * BP: ceilometer-fuel-integraition
  * HA and simple deployment
  * general MySQL backend for ceilometer
  * tested on CentOS 6.4
  * need verification of Ubuntu support
Fix for rabbit_hosts flag in ceilometer
Fix duplicate assignment rabbit_host
Merge pull request #854 from rsokolkov/master-ceilometer-havana

Master ceilometer havana