Feature: pengine: Addtion of the clone resource clone-min metadata option

The clone-min option allows us to represent how many cloned
instances are required to be runnable to consider the cloned
service as a whole available.

Example: We have 3 cloned rabbitmq instances and set clone-min=3
Rabbitmq requires quorum, so at a minimum 2 instances of rabbitmq
must be available for the rabbitmq clone to be considered active.

From there, the clone-min option works automatically when creating
ordering constraints against the rabbitmq clone.

Example: start rabbitmq-clone then keystone-clone.
When clone-min=2 on rabbitmq-clone, that means 2 instances of rabbitmq
must be started before any keystone-clone instance can start.