Health share:
Link the health of two players with the /link [player] command.
Health will update upon damage or regeneration. Works better without natural regeneration on the server.
Upon logging out or using /unlink the healthsharing stops.

Commands:
Link: /link [player] links the players health to another player.
Unlink: /unlink Removes the link between the two players.
Loop: /loop shows all the currently linked players on the server in pairs.
Unlinkall: /unlinkall unlinks all the players who share health with each other on the server.

Permissions:
- Linking or unlinking requires no permissions.
- sharedhealth.loop: gives permission to loop through all linked players.
- sharedhealth.unlinkall: gives permission to unlink all players on the server.