Support super panels

[damithc]

We should consider collapsing different types of panels (dynamic, morph, etc.) into one 'super' panels.
e.g.

<panel src="/docs/loadContent.html" title="some title" 
 expandable collapsed|expanded|minimized type="seamless|primary|warning|...">

</panel>

The presence of src indicates it is a dynamic panel.
A panel can have icons to expand, collapse, minimize, and expand all.