- base library dojo, widget library dijit

- unified event processing: wiring up using dojo.connect, can connect
  DOM events as well as dijit widget events

- widget creation:

  - widgets live in a DOM node (the widget's "top-level node";
    property .domNode)

  - can be created fuly programmatically (no reference in HTML), but
    most of the times there will be a HTML element containing basic
    attributes of the widget, which will be parsed by dojo to create
    the widget at runtime. The required "dojoType" special attribute
    specifies the dijit type name. Example:

    <button id="showDlgBtn" dojoType="dijit.form.Button">Click Me!</button>

    In the JS code, you'd dojo.require("dijit.form.Button"), at which
    time the Button widget's code is loaded. The HTML will be parsed,
    the button element found, and the corresponding widget object
    created. This parsing is done automatically if you have a
    djConfig="parseOnLoad: true" attribute of the body tag, or it can
    be initialized programmatically using dojo.parser.parse().

    Once created, a reference to the widget can be obtained using
    dijit.byId("mydialog"). If you have the DOM node of the widget,
    you can also get the widget using widget=dijit.byNode(node). (this
    is the reverse to the widget.domNode property mentioned
    above). This is useful e.g. in event handlers that get the DOM
    node the event occured on.

    All widgets currently existing on the page are stored in the
    dijit.registry.

    - TODO: describe programmatic creation, attributes, ...

  - various overridable callbacks are provided that're at specific
    points during the widget's initialization/lifecycle

    e.g.

    postMixInProperties: function() {
        //at this point, attributes from the markup (or from the params hash for programmatic creation)
        //have been mixed into this instance as properties
    },