Add missing alt attributes to images so output validates

Helps with troubleshooting HTML errors.
Update Footer to use new semantics for hiding content on smaller viewports

Bootstrap 3 uses hidden-sm instead of hidden-phone.
Update markup in status bar to be Bootstrap 3-compliant

Refactor navbar markup for new conventions, replace spans with col classes, encode URL parameters to be valid HTML.
Update all mini buttons to be extra small buttons

Bootstrap 3 says btn-mini is now btn-xs.