Start of preventing users from interacting with messages when they are not in the room.

The issue was that box attempted to resize before it was cleared. I added a callback that is called after `input.val = ''` which fixes it.
Relates to https://github.com/RocketChat/Rocket.Chat/issues/3037

- Edit buttons to save and cancel no longer submit the form
- "More channels" link has 100% width again
- Fix "New messages" button to overlaps date division
- Fix "Jump to recent messages" to 100% with again

Show correct menus on mobile

Katex as well as multiple line help was not being shown
because of a typo and a missing function.

* Added the ability to create larger emojis by editing sprites.css.
Changed renderMessageBody.js so that if a user's message contained only an emoji, it appears 3x as large.

* Fixed spacing and equality issues.

* Update renderMessageBody.js

Cosmetic fixes

* add katex formatting tip when katex and formatting tips are both on

* it's RocketChat.katex, not RocketChat.Katex

* link to KaTeX website. moved to a more logical location in formatting tips

Add data-role attribute to role tags, allowing custom CSS

Add setting to disable displaying role tags

Message popups are invoked in chat window, when selecting channel suggestions, emoji, and more.
Before:
- suggestion is moved up/down on keyup
- long holding does nothing

Now:
- suggestion moves on keydown, which feels much more natural, as it fits behaviour from other parts of OS
- long holding cycles through all options

* Remove unused helpers in some templates

* Improve and standardize UI for lists

* Create an API to add access room validators

* New page to see livechat sessions

* Add external.js to .eslintignore

* Return publication error correctly

Closes #2956

* Permalink

* Add message attachment on jump to message link

* Change the check for root url

* Remove commented code

* Room Roles

* Replace arunoda:streams by rocketchat:streamer

* Getting user roles

* Add stream notifications for adding/removing user and room roles

* Fix event broadcast

* Update version of rocketchat:streamer to 0.2.0

* Call subscribe after adding user to role

* Update rocketchat:streamer to version 0.3.0

* Notify broadcast

* Notify and broadcast as default

* Update rocketchat:streamer to version 0.3.1

* Update rocketchat:streamer to 0.3.2

* Improve broadcast auth

* Fix LiveChat Streamer