Initial version of simplified, code-generated demesne focus/obligations slider laws

In retrospect, I need to loosen the rules upon the strict maximum and minimum law offsets afforded so that demesne focus sliders can trade-off over a range that covers at least one full slider in each directions' worth of levies/taxes for their vassal class.  Currently, they'll only cover a single slider increments' worth of trade-off.

Nevertheless, it'd be nice to actually see this in-game at least.