Should ruler position have bounds?

[stemilymill]

For phetsims/qa#889

beersLawLab.beersLawScreen.model.ruler.positionProperty can be set using setValue to positions far outside dev bounds.

If the window size is manipulated such that the ruler becomes visible, clicking on the ruler will return it to default position.

[pixelzoom]

My recommendation is to close this issue as "won't fix". Over in phetsims/ph-scale#270 (comment), we concluded that, for movable things that have drag bounds, we're not going to prevent the PhET-iO client from positioning them outside their drag bounds. It doesn't hurt the sim, and the movable thing (ruler in this case) will snap into the drag bounds as soon as the student starts dragging it. If they position it outside the bounds of the browser so that it's not visible/draggable -- well, don't do that.

@arouinfar if you agree, please close. Otherwise let me know what you'd like to do.

[arouinfar]

Completely agree @pixelzoom, closing as wont-fix.