Added optional subtitle to page template.
Added better CSS formatting for error and general messages.
Updated cronjobs, nodes, enquiry types and inventory controllers to use subtitles and to display the banner on every pages (inc. view, edit, delete, etc.).
Updated banner so uses subtitle to determine which option it should display in a bigger font due to it being the current page.
Updated deployments controller to use subtitles and banner on every page. Added current deployments page. Improved formatting of usage pages (centralisation).
Updated template controller so it more similar to existing controllers.  Tidied up so it is easier to use as a template for a new controller.