Emoji: Replace :roll: with unicode 2 twemoji version
|Reported by:||Joen||Owned by:||pento|
Steps to reproduce: write a post with the :roll: smiley inserted.
Notice that it maps to /wp-includes/images/smilies/rolleyes.png, which is a custom smiley we drew to match the Twemoji style. We did this because Twemoji version 1 did not have a "face with rolling eyes" emoji at the time.
But Unicode 8.0 does, and so does the new version of Twemoji: https://s.w.org/images/core/emoji/72x72/1f644.png
Suggested fix: keep the :roll: string, map it to the Twemoji image now, and retire the old smiley PNG file.