[jfkistub] Least populous splitline

Modify the shortest splitline algorithm for redistricting to minimize the line integral of population density along each splitline.  This will avoid cutting cities.

Instead of greedily choosing the minimum splitline at every step, consider the problem of choosing splitlines which globally minimize the total cost function along the lines.  This is applicable to the original splitline algorithm as well, assuming constant population density.

An interesting way to outsource the difficult computational problem is for the state to make it a contest: the official districts will be the best submitted (meeting criteria) within a time frame.