Release notes for percona agent 1.0.10

docs preview: http://cloud-docs.percona.com/en/rn-1.0.10/release-notes/1.0/1.0.10.html
More new features from Changelog:
  * Add data-spooler-count, data-spooler-size, and data-spooler-oldest statuses
  * SIGUSR1 causes agent to dump status to stdout (percona-agent.log)
  * SIGHUP causes agent to reconnect its command websocket