TP: major cleanup, venue -> assignment.
TP minor fix
TP: some other fixes.

Conflicts:

	controllers/submission.py
TP: better log levels for keystore.
Added a function useful for diagnosis
TP: the date of a submission is now updated when the submission itself is updated.
TP: better date format.
TP: Some small UI changes.
TP: removed run reputation system research, as it is not used.

Conflicts:

	controllers/rating.py
TP: Reads the comments from the key-value store before populating review form.
TP: better view of submissions to review.
We now delete venues.
Fixed deleting venues.