Attempts to make getting combinations of things easier with the use of gears and simple numeric states!

Example

``` use gear_combos::*;

let mut gears = vec![Gear::new(2),Gear::new(2)]; let combos = getgearscombinations(&mut gears); assert_eq!(vec![vec![0,0],vec![1,0],vec![0,1],vec![1,1]],combos); ```