Include round in process state log message
Fix PD heartbeat handling

Ensure round # is treated as an int.

OOIION-705
Refresh node IP information even when the instance state stays the same

This is a workaround for OpenStack, which returns the local hostname as
the public hostname for some time during the launch, even though the
instance is already running. At each IaaS query, we check if the
instance IP information has changed. If it does, we send a state update
to EPUM.

We make sure that EPUM does not process out of order messages by using
an update counter.
Add domain sensor support to epum
Allow opentsdb adapter to query for domain sensors
Copy paste typo
Use domain sensors when calculating scaling value
Don't reuse OpenTSDB connections.

The server can eventually just hangup on us, so it's best to use them
once and close them
Remove stray debug.
Add optional exceptional.io extra
Try to catch and recover from all terminator errors
Play with testing ZK conn failures via TCP proxy
Remove unused leader kill test log-saving logic
Provisioner ZK proxy kill tests. And fixes!

Use KazooRetry to wrap all ZK calls: automatically retries
on transient failures.
EPUM ZK tests and fixes
More ZK proxy tests and fixes
Fixed bug in EPUM instance state handling

De-duped state comparision code to simplify
Add a prefix to decision engine logging
Add fail_fast to provisioner threads.

If a provisioner thread dies, it will take down the whole provisioner
process, which should help with debugging and reliability when deployed
with supervisord
Run terminator death in a child to avoid killing the main process