* copyright headers for agent folder
* Ignore test data files
* fix proto files and remove headers in agent/uiserver folder
* ignore deep-copy files
* copyright headers for agent folder
* fix merge conflicts
* copyright headers for agent folder
* Ignore test data files
* fix proto files
* ignore agent/uiserver folder for now
* copyright headers for agent folder
* Add copyright headers for acl, api and bench folders
This adds two goroutines to perform autopilot tasks on the leader - one
to monitor the health of servers and another to periodically clean up
dead servers with a limit on removal count. Also adds a new http endpoint,
`/v1/operator/autopilot/health`, for querying this information through an
operator RPC endpoint.