Full functions for add/remove assignments
fixed bug for adding new category
Merge pull request #79 from LilongHuang/lilongBranch4

Full functions for add/remove assignments
Making TestHelper produce reasonable grades.
Adding some more statistics methods.
Incorporating more statistics and tooltips into the html export.
Placeholder for summary tab.
Merge pull request #80 from spockNinja/export_statistics

Export statistics
Merge pull request #14 from spockNinja/master

asd