Display notices on the site report and improve UI for scheduling a scan

This should probably be two pull requests, but I got carried away.

You can preview the changes here: http://ucommfairchild.unl.edu:8001/sites/774/

This change adds the number of notices and errors to tables, along with the grade.  The goal is to help the developers prioritize pages, and to bring notices to their attention.  This change increased the width requirement for the tables (especially the "hot spots" tables), so the site report has been redesigned 'in page navigation'.