- New plugin `converse-smacks`
- New config option `enable_smacks`
- Rename session cache id from `converse.bosh-session` to `converse.session`
- Refactor logout and login as consistently used api methods
- Refactor session cache to store per JID

Fixes #316

So that we can specify defaults

When a synchronous event is fired, Converse will wait for all
promises returned by the event's handlers to finish before continuing.

if the page is reloaded while the nickname form is shown

We now use CSS to make sure that the controlbox and toggle is always on the far right.

- Remove section on UMD
- Add section explaining how to override templates
- Add overrides example to the relevant section
- Mention composition to add methods to existing classes

- Upgrade to latest commit in Strophe
- Import individual Strophe dependencies
- Replace strophe plugins with code in Converse

Also fix issue where trimmed headline chatboxes don't show the proper
color

- Take locked_muc_domain into consideration in chatroom display name
- Use getDisplayName when rendering the heading name
- Give preference to bookmark name if it exists

* Mention plugins for OpenFire and Prosody
* Mention demos on conversejs.org

when receiving an `unavailable` presence for ourselves.

Refactored moderation by moving certain methods to the model and
consolidating setting of roles and affiliations into new methods.

and also first check whether we have an occupant with that nickname.

Since roles are session based, it doesn't make any sense to try to
modify the role for a user not in the room.

When using `auto_login` and logging out, Converse gets stucks with an infinite spinner.

- new config option `singleton`.
- new plugin `converse-uniview`
- removed `converse-embedded`.
- various CSS changes, to properly render an embedded full app
- don't re-open cached and non-autojoined chats in singleton mode

The goal here is to extend the `embedded` `view_mode` so that the full app can
also be embedded, not just a single MUC or private chat.

To do this, we'll need to differentiate between multi and singleton chat apps.

* A singleton chat app contains only a single chat.
* A multi-chat app can contain zero or more chats

So we introduce a new config option, `singleton`, which when used with
`view_mode` set to `embedded` will determine whether a single chat or the full
app is embedded.

Similarly, in `overlayed`, `fullscreen` and `mobile` view modes, `singleton`
set to true will allow only one chat within the parameters of that view mode.

We're appropriating the word `singleton` and introducing the concepts of
`uniview` and `multiview` (see a785ca8) to cover what was
previously meant with `singleton`.

updates #1297