* Add support for sending room-local emoji
Does not add support for sending a room's emoji outside of that room, but enables users to
send an emoji if the packs in a room support it. Does not include room emoji in the
picker YET.
* Amend PR #209: Don't freak out if the `pack` tag is missing
* Amending PR: Refactor emojifier, use better method for retrieving packs
* Amending PR: Improve resiliance to bad data in emoji state events
* Amend PR: Remove redundant code, fix crash on edit
9ea9bf4035