So that it doesn't depend on it's element already being in the DOM

Also added a new jasmine spec for this as well as jquery.tinysort to do the
sorting.

Also add flush method to converse.js (used in ClientStorage tests)

Can succesfully connect now, but still need to get rid of ajax calls to @@xmp-userinfo, and replace them with
VCards.

This is necessary because each open tab in the browser is its own resource.

TODO: Ideally we should differentiate between resources in the browser (using
converse.js) and other resources (i.e from a desktop client).

- This allows multiple open tabs (which is each its own resource) to be aware
when one tab sent a message.