STYLE: fix typo in Ajax coverage display

git-svn-id: https://www.kitware.com/svn/CDash/trunk@3349 91079597-3006-4846-9bd3-4f3fb3d139a7
ENH: make the label / percent coverage table sortable

git-svn-id: https://www.kitware.com/svn/CDash/trunk@3350 91079597-3006-4846-9bd3-4f3fb3d139a7