Semantic elements

I'd like to add semantic/structural div aliases as per http://www.w3.org/wiki/HTML_structural_elements#Enter_HTML5_structural_elements

Is this something appropriate for OJ?  My naive approach simply registers div functionality under several alias tag names, I'm not sure if this is the right implementation idiom, comments welcomed.

```
# register semantic/structural aliases
for nodeName in [ 'div', 'section', 'header', 'footer' ]

    OJ.nodes.register nodeName, (options, owner = OJ.body, calledFromFactory = false) ->
```