Include entity capabilities hash in outgoing presences

Also, started some work on using jsdoc for rendering API documentation.
Ideally that would go into a separate commit but that would take ages to
untangle.

- For roster contacts, only show remove icons on hover.
- Show light background color when hovering over an item in the
controlbox.

Ideally this background color will be 100% of the controlbox width, but
I'm not opening that can of worms now...

Update the occupants list when occupants are added/removed from the
member lists.

Refetch the members lists when adding a new member via invite

updates #1099

I find it useful to be able to close them

- Show users who are registered on the different members lists
- Show badges indicating user's roles and affiliations

It's now possible to set your VCard via the UI and via the API

And instead implement it ourselves.

This solves a bug with that plugin whereby the connection handlers are
added to early and are therefore never fired.

Also fixed a problem whereby entity items are queried for features
before the features have been fetched.

so that it's applied in all cases where archived messages are fetched.

instead of wrongly checking the bare JID

Otherwise the model gets removed mid-creation, which causes the
`url required` error from Backbone.