Since we're already using jquery-ui for other stuff, it makes sense to use it
for tooltips too, instead of using an old-school-written-in-2009 1300 lines
steaming pile of javascript named wz_tooltip.js
The inline javascript used with the cancel buttons
was only used to change the location.
Instead of doing this, it's easier to wrap
the button in a tag.
This is related to #909.