Render emotes as the user types

Changes can be tested on abadev.

Render emotes as the user types. I'll leave a TO-DO list with small tweaks to remind myself here. It should be Mostly Working™ 😎

• I forgot to make clicking emotes in the emote list work lol
• The chat box is missing the placeholder text now because I haven't yet figure out how to do it with contenteditable
• Custom emotes in PMs with yourself are broken.
• Emotes are case-sensitive. Annoying. I should make them case-insensitive.
• Up and down arrows don't work for navigating the autocomplete menu.
• Make chat box more modular and add emote completion/fancy rendering to sticky message dialogue.
• Remove old auto-complete code.
• Make autocomplete work mid-sentence.
  • E.g. hello :chen<cursor here> world
  • Also make cursor not jump around when auto-completing mid-sentence
• Double check how the cursor is handled when pasting/auto-completing
• Make autocomplete match sub-strings, not just the beginning of the string.

If you find any issue/tweak, please poke me :D

This PR also makes the "About Me" Summernote editor in /mastercontrol/edit look exactly like it did before I added moderator notes.