Note that this commit is also fixing various mistakes in emojis.
Some of them have been fixed manually in db.json/data.js/groups.json and will need to be fixed in emoji-db gem.
- frowning was using slighty_frowning
- slightly_frowning was using frowning
- grinning_face_with_smiling_eyes was not defined
- fronwing_face_with_open_mouth was not defined
