Fix hashCode() and equals() for AutoRefTeam

Should be based on fixed values. Using getPlayers() in
hashCode() means that team lookup fails if the members
of a team changes, causing problems for the vast
majority of AutoReferee.
Add metadatable fields for common classes.
Provide variadic sync broadcast methods.
Fix NPE in VehicleDamageEvent
Update javadocs for 229919b
Refactor TNT ownership code for plugin visibility.
Refactoring method names to improve code readability
Show start regions in `/zones` command
Add command to cap height of team regions

Only currently effective for cuboid regions
Add a simpler means of breaking ties goal (needs testing)
Improve the way players are teleported in/out of worlds.
Improve spectator mode. Buffer gamemode changes.
Merge branch 'master' of git://github.com/rmct/AutoReferee