Lots of changes (listed below)

- refactored DiceBag into it's own file for easy editing. GoIP DM and
Player versions now add their own behavior to the roll button after
creating the dicebag.
- removed a system.out that got left behind in debugging.
- added description bar to dicebag for players and DMs to be able to
tell which dicebag corresponds to which of their rolls.
- got rid of a lot of "warnings" eclipse had.
- improved dicebag GUI (specifically textbox alignments) so it is easier
to read.