Contractor leeway

The contractor will now form 30 contracts by default, and spend 50% less money on them. I have not added testing yet because I would like some feedback on how the lowballing was implemented. In short, I modified maxSectors to return half its previous value. The contractor calls maxSectors whenever it is calculating how much to spend on storage, so this seemed like an easy way to implement lowballing at the root, rather than modifying every function that forms or renews contracts. Still, I am wary that this may be too clever.