Additional checks

[Matistjati]

There are some footguns that would be very nice to check for. Examples:

1. You can't use Java output validators in Kattis.
2. There are non-obvious conditions dictating whether IOI scoring is allowed on a particular problem in Kattis
3. Multiple output validators are not supported in Kattis (?)
4. You can have at most 1GB of testdata in total in Kattis
5. Kattis uses git, so it's annoying for them if any file is larger than 100MB
6. Minimization problems are not allowed
7. You may not have negative scores
8. You may not have shortnames longer than x characters
9. Kattis won't render Latex problem names as latex in the html view (i.e. if you use LaTeX in the name you must provide plainproblemname)
10. Using pragma(avx2) without some jumping through some hoops gives compile error on Kattis' GCC version

In some sense, these checks should not always be enabled. One idea is to have groups of optional checks, i.e., "ioi", "kattis", etc. To determine if this is the best approach, I want to know of other footguns people have been shot by.

Also, this should be used to let contest systems indicate which parts of the spec they support (multipass, markdown statements, static validators, latex problemnames, etc.)

[niemela]

1, 3, 4, 5, 6, 7, 8 should be ERROR with --kattis.
9 is a WARNING (if not handled) with --kattis.
2, 6, 7 should be ERROR with --ioi.

We should also add --icpc, which should probably check for scoring problems.

Also, we should ask DOMjudge and PC^2 what if anything they would want under --domjudge and --pc2.

[niemela]

@clevengr @eldering ^ ?

[eldering]

For DOMjudge I think:
2, 3, 6, 7 should be ERROR
1, 4, 5, 9 should be WARNING (as in: it will work, but not ideally or is not recommended or deprecated)

We currently don't support scoring yet, but @meisterT is working on it, so things may change.

For 8: if this is the label according to https://ccs-specs.icpc.io/draft/contest_api#problems then our internal limit is 255 characters, although that would render horribly on the scoreboard and other places.

For 10: I'm not 100% sure but I think this would compile fine.