Removed suburbLayoutAction from AjaxController

Removed suburbLayoutAction from AjaxController as it has been moved
to pure JS for speed and is no longer in use.
Moved Layout to base/default, added ajax

Moved the frontend layout files to base/default
so that it can be loaded regardless of the
current active theme.

Also added lines for Collivery Ajax calls and
added jquery and our own JS to the
checkout page