It's currently only used by the MUC header to render URLs in the subject

- Don't replace entire textarea when entering a second emoji
- Focus emoji picker on tab completion when it's already opened

for emoji related data

Fixes #2126

(i.e. not on reconnection)

the first time it's opened

Changes how rich message markup is generated and kept track of.
We now have a MessageText class which subclasses String and which keeps
track of the rich markup associated with the message.

Wait for emojis to be initialized before parsing MAM messages

- Declaratively render the emoji picker dropup
- Got rid of converse-emoji-views
- Adapt OMEMO to the new buttons stuff
- Make emojis json global, to try and speed up tests
- omemo: Move functions to the top of the module

which throws and error and causes tests to fail

Created a web component registry and exports components as modules in order to facilitate their customization

So that it is the same size as in the 'fullscreen' view mode

to overcome cross-site restrictions on using the `use` attribute of the `<svg>` element.

So that components can use `listenTo`