Tooltips with stick flag recreated without clean-up

[ain]

Steps to reproduce:

1. Create scrollable container with element that triggers tooltip at the bottom of scrollable area
2. Initialise tooltip with stick option set to true and without any other options
3. Scroll down
4. Roll over element that triggers tooltip
5. Scroll up few pixels
6. Roll over element that triggers tooltip

What happens: Another tooltip is created overlapping already existing tooltip:

What should happen: All previous tooltips of same instance should be removed.

[ain]

Only happens on Safari 10.1.