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
This was never confirmed, it was just a theory, so we added `-mysql-max-user-connections` to the installer (default: 5) which adds `MAX_USER_CONNECTIONS` to the agent MySQL user on install. Therefore, this safeguard only affects new installs (unless user manually adds the same limit to existing agent MySQL users).