Cleaned up some synchronization around ConnectedUsers.users while I was in there. The list itself wasn't synchronized, which could have been a slight problem.
Users can specify an identification code when they connect (8-100 characters), only if they are using HTTPS. This code is combined with their nickname and a server-side secret, hashed with SHA-256, and condensed down to 64 bits by XORing every 8th byte with each other, and finally converted to base64 (with the trailing = removed). This code is displayed in a tooltip when hovering over the user's chat (TODO: mobile way to view it).
Sigils have been added to be displayed before the user's name in the chat. Admins get @, users with an ID code get +, and normal users get nothing. The IS_ADMIN field is now deprecated, as this can be determined from the user's sigil. It will be removed eventually, but is still being included in events even though the official client should not be using it anymore.
Kicks and bans are now always displayed to all users, even if the server isn't transmitting quit events normally.
This is in preparation to support multiple tabs, which will provide a
separate chat tab per running game.
Signed-off-by: Matt Mullins <mmullins@mmlx.us>