* Global namespace issues have been addressed.  Everything in GradeBook.js is now owned by AN.
* Added sorting on assignment columns - can only sort in ascending order.
* Added highlighting of columns on hover.
* Fixed styling issues where pie chart width to fit within viewing window.

git-svn-id: https://plugins.svn.wordpress.org/an-gradebook/trunk@888483 b8457f37-d9ea-0310-8a92-e5e31aec5664
added list-tables.css

git-svn-id: https://plugins.svn.wordpress.org/an-gradebook/trunk@888485 b8457f37-d9ea-0310-8a92-e5e31aec5664