Antag scaling changes

1, Makes traitors in traitorchan scale properly, instead of always
creating (5-numberoflings) traitors like in last round. It would be
easier if we just called a ..() for traitor scaling but then we could
have lingtraitors...
2, Decreased doubleagents amount just a bit, by popular demand
3, Increased the number of players required for Nuke, so the OPs won't
be forever alone ;-;
Merge pull request #93 from Profakos/antagtweaks

Antag scaling changes