Dismiss highlight tooltip when clicking elsewhere on the page.
Dismiss highlight tooltip when clicking elsewhere on the page.

Test Plan:
1) Highlight something.
2) Click elsewhere!

(Also test on the remove highlight tooltip as well by creating a highlight and then clicking on it.)

Reviewers: sean, mattdunnrankin

Reviewed By: mattdunnrankin

Subscribers: jared

Differential Revision: https://phabricator.khanacademy.org/D29515

learningequality/perseus,ariabuckles/perseus,ariabuckles/perseus,ariabuckles/perseus,learningequality/perseus,ariabuckles/perseus