Projects "future stuff"

[ethteck]

• [x] Replace icon_url with FileField (static uploads)?
• [ ] Ways to sort the function list (number of attempts, ProjectFunction asm size, etc)
• [ ] Filter by matched/not-matched
• [ ] Handle matched_in_repo: true on frontend & disallow create_scratch of the ProjectFunction
• [ ] ~~Store target asm per-ProjectFunction instead of per-scratch~~
• [x] Replace "start attempt" with "continue attempt" if you have one
• [ ] Allow pull with a token query parameter (for webhooks)
• [x] Link to repo from projects page (and other info)
• [x] Project descriptions
• [ ] ~~Grab existing source_code from NON_MATCHING section in the c file if there is one~~
• [ ] UI for project maintainers to update config without the django admin panel