Minor upgrades
Import mouseview ES6-style and separating drawing the overlay from showing/hiding it via opacity. For the latter, see: https://github.com/u01ai11/MouseView.js/issues/17
Import mouseview ES6-style and separating drawing the overlay from showing/hiding it via opacity. For the latter, see: https://github.com/u01ai11/MouseView.js/issues/17
This will create a new commit in order to revert the existing changes.