Bug fix release

There are no substantial changes from the previous release, this is mostly a Django update and bug fix release.

Bug fixes:

1. Ensure files are in ASCII to prevent spurious compilation errors or crashes (#96)
2. Fix a case mismatch issue with email IDs (#94)
3. Fix a leaderboard bug; leaderboards for contests now only use problems from that contest (#95)
4. Fix a CDN issue (quilljs is banned on certain networks) (#97)

Minor bug fixes, updated Django versions

There are no substantial changes from the previous release, this is mostly a Django update and bug fix release.

Bug fixes:

1. Generate .log file after TLE / OOM (#93)
2. Fix inconsistent lengths for CharField when using uuid.uuid4. (2439d30)
3. Fix internalization bug in Django (6ff2846)

User Manual, contextual errors and handler refactor

Highlights

• autojudge now has a user manual, where people willing to use autojudge are guided with respect to basic functionality provided by the software.
• handler.py was refactored to make functions less try-catchy.
• Errors thrown on forms now pinpoint the exact fields causing the errors, leading to better localization.
• superusers created via Django now are registered now have a dummy @autojudge.superuser domain.
• add_person_rgx_to_contest is removed from handler.py.
• submission_watcher_saver.py doesn't run in a spinlock-y manner if number of submissions are lower than a threshold, it instead sleeps for a while.
• Miscellaneous documentation improvements.