Fix and finish balance command

Balance is now Integer instead of Double
Fixed balance command not returning balance which fixes #6
Added remove balance
Added add and remove balance for other players
Fixed typos in locale
Fixed balance format in locale
Fixed players who does not have permissions being able to give
themselves money
Players can view other's balance
Players no longer have negative balance and removing more than the
player's amount sets the balance to zero if using the command
Fixed player balance not saving