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.