add absolute/relative option in config file

[spencerrecneps]

This would allow for absolute or relative scoring of destination access. Current default is relative (points are dependent on the number of high stress destinations, so if there's only one school in the area you get full points if you can get to it on low stress, even though you only have access to one school.)

Allowing relative vs absolute allows to define categories where access is important regardless of what you can do on the low stress network. So you could get punished for not having low stress access to a grocery store, even though there isn't a grocery store anywhere near you.

Can be built as an entry in the config file for each destination.