Make settings sound less city-ish

[evz]

As I'm going through and documenting the jurisdiction specific settings that one must change to get this going, it occurs to me that the way they are named assumes that this is going to be used for a city when in fact any legislative body could have a councilmatic (including a transit authority). Not super urgent but it seems like we ought to make the setting names reflect that. This will involve updating django-councilmatic to look for the new setting names.