Fixes a TypeError: Cannot set property 'innerHTML' of undefined
                    at o (Chat.js:61)
                    at Object.updateChatConversation (Chat.js:271)
that is thrown when joining a conference with messages already set to the chat. The error used to remove a strophe handler and chat was not working at all for those seeing the error.

https://github.com/jitsi/jitsi-meet/pull/1397 (React Toolbar) is huge at
the time of this writing. In order to reduce it, I'm extracting changes
not directly related to React-ifying the Toolbar such as added jsdocs
and source code formatting.

Enable ESLint on jitsi-meet with the same configuration and the same
goals as in lib-jitsi-meet.

The extension of the file modules/UI/side_pannels/chat/smileys.json
suggests that the format of the file is JSON. However, it contains
JavaScript RegExp instances which do not represent valid JSON. Such
discrepancies between file extension and format cause failures in
certain tools such as Webpack. Convert the file (both extension and
format) into a valid ES2015 module.

Receiving messages docks the toolbar to be able to see number of unread messages. We need to undock it when we read the messages. We skip undocking if we are not in video mode (on large), cause stuff like youtube video share is docking/undocking the toolbar.

This reverts commit 93648f361b.