Adds plusminus and minutes to the cat-stats extension.

As JGibbs asked, I add +/- and minutes to the cat-stats in the order he wanted.

Minutes are rounded to one significant digit, which means that the time given in the csv file can't be more that 3 seconds away from the time truly spent in the game.

+/- handles switching teams "correctly". For instance :
Early middle of the game: 1-0 for red team, Some Ball 1 enters as a red ball. (+/- of 0)
Middle of the game 3-1 for red team, Some Ball 1 switches to blue (+/- of 1)
End of the game blue team wins 7-4, Some Ball 1 still blue. (+/- of 5+1=6).
Some Ball 1 will have 6 as their +/- stat