Added new alias

The reason why i find this usefull is so i don't have to edit it myself everytime i update HeavySpleef.
This will also make more sense since you added support for a Splegg alias in signs, so when you can join a sign named
[Splegg]
Join
Why shouldn't you be able to write /splegg leave ? If then it begins to be a problem with conflicting plugins (there is only http://dev.bukkit.org/bukkit-plugins/splegg-game/ and http://dev.bukkit.org/bukkit-plugins/splegg/ which there is no reason to use if you use HeavySpleef)