* Fixed Firefox bug where student list would not display.
* Added assignment menus to assignment headers and removed the corresponding buttons from grade-book view.
* Added student menus to student row headers and removed the corresponding buttons from grade-book view.
* Cleaned up code.

git-svn-id: https://plugins.svn.wordpress.org/an-gradebook/trunk@1038634 b8457f37-d9ea-0310-8a92-e5e31aec5664