defined 3 enhanced mobile navigation patterns. Setup code comments to operate all navigation patterns in their own namespaces so that there are less conflicts.

* .no-js #nav (basic fallback navigation)
* <768 .js .nav-left #nav (enhanced mobile nav)
* <768 .js .top-left #nav (enhanced mobile nav)
* <768 .js .expand-left #nav (enhanced mobile nav)
* >768 .js #nav (enhanced desktop navigation)

Signed-off-by: Joanthan Haslett <jon@dashmedia.com.au>