This changes:
1. use aodhclient to manage OS::Ceilometer::Alarm
resource, including create, update, delete, check, suspend,
resume and show.
2. rename OS::Ceilometer::Alarm to OS::Aodh::Alarm
3. considering to compatible with old templates with resource
OS::Ceilometer::Alarm, set resource_registry to map Ceilometer alarm
to Aodh alarm
Blueprint migrate-to-use-aodh-for-alarms
Change-Id: I6e2d14f15a345b927b53adc237cf2bf4010842f0