LastCall

v1.3:
can now specify custom countdown message, set default countdown time in the config, and can use /lastcall [time] [song] to start the shutdown time with a specific time.
v1.2:
/play and /lastcall can now use the item ID's of the discs! Fixed the message for using /play with a disc in your hand, it now uses the correct names.
v1.1:
Modified /play to allow players to play the disc in their hand when used without any parameters. Attempting to use it with something that is not a music disc yields "That is not a music disc!"