User wasn't being removed from the roster if their buddy unsubscribed.

- Also, use the browser's confirm dialog, to remove the dependency on jquery.ui

- Uses Backbone.localStorage
- Unsubscribing/removing contacts from this cache is not yet tested/implemented

- Try to clear up the confusion between presence_type (i.e type attr) and
  chat_status (i.e <show> element).
- Properly set chat status and custom status message.

- Added 'show' element
- 'busy' must be 'dnd'

Also, don't hide the controlbox in the beginning, no need to.

- Don't do an ajax call when a user wants to subscribe. We wanted to get the
  user's fullname, but this is now handled via vCards
- openChat is now only for roster items. Call showChat for controlbox and
  createChatRoom for rooms.

This time when a message is received for the first time.

More code optimizations

- Chain calls on initialize method of RosterView
- Moved dom insertion out of loops on initialize method of
  XMPPStatusView

Wrap this with jQuery only once in subscribeToSuggestedItems; Same thing with presence in presenceHandler

- removed extra jQuerify wrapping of message at onChatRoomMessage
- Construct an array of strings and add it to onChatRoomRoster only
  after loop is done in order to have only 1 dom insertion

- Chained call to render and show methods of ChatBoxView
- Cached target for subscribeToContact
- Removed check of length > 0

- Removed situation where extra data passed in keyPressed was overriden
  with the same result because of the two assignments inside the if
  statements
- Cached fullname and presence_type at initialize of ChatBoxView