Fix and improve autoscaling.yaml

Fixed a problem: the health monitor's delay was less than its timeout,
which is now disallowed.

Added stack outputs that show and explain the webhooks and a
ceilometer query that selects samples about VMs in the stack.
Also added an output that shows the entry IP address.

Change-Id: I11313f05d885cb0698a904f08725227b03617e0c
Merge "Fix and improve autoscaling.yaml"