Hey everyone! Thanks for all the awesome suggestions! I've done a lot of playing around with things today, and I think I finally have the features I wanted working.
ADDED:
Created a config and moved messages to the config file
(messages.yml is no longer used)
Particles on command use (config option to disable)
Cool downs for broll and roll (config option to change each separately)
/diceroller reload command to reload config
/diceroller displays info to players with diceroller.info
bypass permissions for cool down (diceroller.broadcast.bypass and diceroller.roll.bypass)
General Code clean-up
Added prefix for total time from a cool down
Added support for 1.8 (only tested on 1.8.8)
Added multi line support for usage messages
As this is a large update, while I have tested everything I could think of, there could still easily be some bugs, since I am a Java and plugin writing noob, so please be kind and report them, without a bad review. I'll try to find a fix for anything as soon as I can!