Widget Class

A class to handle desktop widget. The purpose is to be extended by menu, taskbar, and whatever widget you can think of.

What is it supposed to do:
 - Register the widget in os.widget in example (instance of the object properties, like os.modules.run)
 - Add the widget to the desktop
 - Move the widget
 - Remove the widget
 - ...

Possible properties:
 - name
 - container
 - options
     - movable (default: false)

possible methods:
 - add (inject into container, container as argument)
 - remove (remove from dom and register table)
 - move (change position in register table?)

See box.js / panel.js heritage for an example !