theming functions and jquery_ui version

Hi,

great project;

But i ran into some issues getting the chat bar to work. The current CVS and 1.0alpha, i think, actually assume jquery_ui-1.8.x (although the project introduction specifies 1.7.x).

in jquery.ui 1.7.3 the minified files are called:
- ui.core.min.js etc.
in jquery.jui 1.8.2 they are called:
- jquery.ui.core.min.js
in jquery.ui 1.7.3 there is no (jquery.)ui.widget.js and no (jquery.)ui.mouse.js

The calls to jquery_ui_add in dxmpp/themes/ use the 1.8.2 syntax - i know there are plans to use 1.8 but either state this on the project page or allow 1.7 to work :)

Patch attached; leaving the two none-existing js-files (1.7.3 no ui.widget.js, ui.mouse.js) in there, for you to decide on :)