Improve mobile navigation menu styling

* Remove the display of the current page title (link) -- this was
the original intention, but was unable to do without the clean up
implemented here. It's still a bit hacky...

* Underline effect is now applied to all stylesheets.
Remove local topics var usage within templates

* Rename contact page title to 'Contact Us'.
Move footer div block from site_footer inc to layout

This is for correct usage of the footer block when pages wish to
include additional footer items.

* Do not apply padding-top-offset25 class to form elements;
looks funny on mobile profile...
Introduce experimental 'help' billboard
Make explicit use of tel URLs
Add FontAwesome fonts & CSS