Even when there is no tooltip, setTooltip() accounts for about 5% of the
time spent setting the values on an ArrayEditable, of which about 2% is
Ox.filter.
There only a few possible sets of events, so use object identity rather
than calculating the set difference. In particular, this is a lot faster
when self.options.tooltip is false-y.
(I think it was actually wrong before, anyway:
bindTooltipEvents({mouseenter, mouseleave})
bindTooltipEvents({mousemove, mouseleave})
would (correctly) unbind mouseenter and bind mousemove, but would set
boundTooltipEvents = {mousemove} even though mouseleave is still bound.)
Will Thompson
ec85c7b458