Create TeamSubmission model and presave hook
Refactor validators a bit
Add a little documentation
Fix pre_save tag signal
Add migrations for TeamSubmission
Add an inline admin for code submissions
Enforce unique tag names for each team.
Order team submissions by submit time
Add a page to view a list of submissions
Rearrange sidebars a bit
Add submit button to commit list
Fix style a bit
Create a form to submit versions
Get latest submission by tag_time
Add help text for TeamSubmission
Create an exception to throw when a user tries to tag a bad commit
Throw CodeManagementException when trying to tag a bad commit
Add a page for tagging submissions
Reorganize sidebars for consistency
Fix a bug with popovers on repo page