Units

Adds a "Units" groupbox in the "Style" options tab to choose between bytes (1,536 B), decimal prefixes (1.54 KB) or binary prefixes (1.5 KiB; default). The numbers are localized via `toLocaleString`, rather than using `esb.dot`. I also threw in an option for the space between the number and the unit. I've used the same code for the speed, so atm speed uses up to two decimals, rather than the previous fixed two. (BTW, I've used the `stringbundle` element within the XUL, not sure if that will impact update.)