Add a limited number of blacklists for antag roles for the draft

[Yonnimer]

What it says on the tin, allow players to choose some number of antag roles(i'd say 3) that they can blacklist and won't be drafted for. So, someone can have cult, ninja, and raider wizards chosen and they won't ever get drafted as it, but they can still be drafted for traitor, ling, ect. 

Adding that this shouldn't make it so the player cant' be converted into the role like with cult and rev if it's blacklisted

[Pratepresidenten]

This seems sensible, and would cut down pmuch all of the de-antagging we have to do. I like it.

[Alberyk]

This is a banaid fix on the top of another bandaid fix. Having the draft and then adding some exceptions is really running against the reasons why the draft was added at first and this would make the antag preferences more byzantine than it is already. Voting for dismissal.