* Fixed a bug in the process which prevented "to" contacts from being shown as
existing.
* Add "to" or "both" as classes on the contacts to indicate their
subscription status.
* Delete roster handlers in tearDown method to avoid them being registered
multiple times.

Already testing the first 3 sections of RFC-3921 section 8.2 "User subscribes to contact".

Also, added code to acknowledge a subscription being accepted.
See https://xmpp.org/rfcs/rfc3921.html#substates-ack

Refactor out the code for sending an IQ to add a roster contact.
And then call that from acceptRequest.

Some changes to presenceHandler and handleIncomingSubscriptions to avoid using
strophe.roster as well as to remove duplicate code.

Still part of the refactoring of strophe.roster.

The goal being to be able to remove strophe.roster completely.

updates #359

Fix a timeout bug in chat state notifications

* Update the docs to mention the new ``authentication`` option.
* Update failing tests due to ``prebind`` being replaced with ``authentication``.
* Rename 'manual' value for authentication to 'login' since it's used in both manual and auto cases.

Conflicts:
	converse.js

This caused a bug whereby a chat box would open only on chat state
notifications.

Also refactored the chats.open and chats.get methods so that they now reuse the
same map function and so that chats.get can now return any chat box and not
just already open ones.

Updated the tests to properly test this and updated the docs.

Fix the known bug where a state notification reopens a chat box

Fix the ChatRoomOccupants storage id

Fix the plugin extend function

Add tests for contacts.add API method and make it a bit more compact.
Add entry in changelog.

update #354

contacts.add API to register contacts

- Basic test if the given jid contains @
- use jid as name if undefined

when using prebind and keepalive together.

You don't see visitors without hovering the specific user. So you would have to check everyone by yourself. This highlights them grey. (You're also marked as visitor when you're muted)

Fixes build and test errors due to files having been moved around.
Fixes #351