[Xastir] feature request: per-map levels file

[Jason KG4WSV]

I would dearly love to have a map levels file that i could plop down
beside the actual map file, sorta like a mapname.dbfawk only map
name.levels.

or even a per-directory map levels file.  that would probably work
better in the case of bunches of files like TIGER data for a state.

or a shapefile signature based thing that lives in
/usr/local/share/xastir/config.

I know I can suppress display with a dbfawk, but xastir still has to
process the data, which takes forever.

-Jason
kg4wsv