Improved Antagonist Scaling

![graph_20140902_152058](https://cloud.githubusercontent.com/assets/3828067/4120743/c3e5d522-32b4-11e4-8d34-10b9d6f2f25b.png)
x = population
y = # of traitors
Blue Line: Proposed (Take the lower y result)
Red Line: Current on Sybil

To allow for saner antagonist scaling at high-population while still accomodating low-population rounds.

The PR changes the formula to thus:
Antagonists = min( population / (2* coeff ) + 2, population / coeff )

For traitor, this means
Traitors = min( population / 12 + 2, population / 6 )