Bukkit/Bukkit — comment on commit ec2ccae9793b00aa9b93a536c57268dc44dfd23a
File:  line 0
By Acrobot:

Nope, this wouldn't work. (You can make multiple listeners of one type, with different priority, linked to one class)

I'd rather do:
unregisterEvent(Type, Priority, Listener)
and the 2nd one is fine:
unregisterEvent(Plugin)

Also, it would be nice to have:
unregisterEvent(Type, Plugin)
unregisterEvent(Type, Priority, Plugin)
unregisterEvent(Listener)

:)