Submission: default status to 'Pending'
edit_submission: work on allowing user to see their own submission
Revert "Submission: default status to 'Pending'"

This reverts commit be8bfe8843b30cf791b70d2bd0265d863a160d5f.
submission: different way to make default status 'Pending'
edit_submission: do not show test results for non-judges
edit_submission: return 404 error if wrong submission number is given
edit_submission: make fields read-only if user doesn't have write access
TODO.txt: update