* fix background lighting issue when hovering over fake slots / some
other gui elements (mostly those with tooltips)
* add ability to adjust quantities in routing slip as such: 
    If item on cursor matches item in slot:
        Left click action:
            increment slot stack size by cursor stack size (increment by
1 if shift is pressed)
        Right Click action:
            decrement slot stack size by 1
    If item on cursor is empty
        Left click action:
            if shift is pressed, increment slot stack size by 1
            else if shift not pressed, empty the slot
        Right click action:
            if shift is pressed, decrement slot stack size by 1
            else if shift not pressed, empty the slot
    If item on cursor does not match:
        swap for item on cursor (no change from old behavior)
* remove endermen as default targets for all npcs
* simplify code for default target list