Add ability to support "Scoring" contests

[johnbrvc]

Is your feature request related to a problem?
This is not a problem but development for future contests.

Feature Description:
Currently, PC2 only supports "pass-fail" type contests, that is, contests where a submission either completely works on all judge data (accepted), or fails on at least one judge test case. "Scoring" contests give different number of points per submission depending on how many of just test cases are solved. It is desired to add this "scoring" type contest ability to PC2.

Have you considered other ways to accomplish the same thing?
It is not currently possible to support "scoring" contests.

Do you have any specific suggestions for how your feature would be implemented in PC^2?
Several subsystems within PC2 have to be modified.

1. Reading of the problem data
2. Judging a submission
3. Scoreboard
4. (There are other's as well, I am sure).

Additional context:
May be necessary to implement this for the NAC challenge.