This allows for better desktop notification messages.
Also improved the wording for some of the feedback messages.

after a dropped connection.

- Add new configuration setting messages_storage
- Hardcode the storage for roster contacts and chatroom occupants to `sessionStorage`.

and drop the reconnection timeout to 3 seconds (from 5).

- Added the ability to reconnect to more disconnection causes.
- Make sure the roster is fetched again when reconnecting.

Send a <paused/> notification after 10 seconds, instead of 20.
Auto-remove a typing notification in the chat box after 20 secs instead of 10.

This is to avoid situations where the status notification gets
auto-removed while the typer keeps on typing without long enough breaks in
between for <pause/> states, thereby causing the recipient to not be aware that
they're still typing.

Problem was a race condition between hide and show methods.
Solution was to not hide the chat box during the initialize method.

For each user we keep a list of currently online resources. These resources
were taken from both presence and message stanzas.

Receiving a message doesn't however indicate that the user is online,
especially in the case of archived messages.

This also abused the semantics of messages, which are meant to indicate
user presence.

- Send chat state notifications with type groupchat for MUC.
- Don't show own chat state notifications if received from the server.

The goal is to eventually remove bower as a dependency.

This option is by default set to `true` which entails no changes in behavior
compared to previous versions of converse.js.

If set to `false`, then rooms first need to be configured before they can be
joined by other users (so-called "reserved" rooms).

More info on "instant" and "reserved" rooms here:
http://xmpp.org/extensions/xep-0045.html#createroom

See https://github.com/jcbrand/pluggable.js

so that plugins can have a different mechanism for determining the default
nick.

which if set to `true` will let converse.js automatically take the node part of
a user's JID as their nickname when entering a room.

If there is a nickname clash, then the nickname will be disambiguated by adding
integers to it.

For example, john will become john-1, then john-2 and so forth.

the contact didn't appear under the pending contacts list.

Allows you to easily mention someone in your message.

to make sense within the context of anonymous chat.

when calling `converse.rooms.open`.

It's not stable yet and XMPP server support is very patchy.
However, the nickname form work can be merged into master.

We now need to mock some extra XMPP stanzas being received when a user enters a chat
room in tests.

when they enter a chat room. If they have, we'll use that, otherwise we render
a form where they can specify their nick.

Some chat room tests now fail and still need to be fixed.

This change is with an eye on supporting reserved nicknames, in which case the
user who has a reserved nickname won't have to choose a nick upon joining a
room.