Changes since last version:
* allow 4 decimal digits for QTH long/lat
* implementation of map selector with preview
* implementation of manual time control
* use simulated realtime for countdown till next AOS
* allow running in realtime mode with time offset
* many bugfixes and enhancements
PKGLOCALEDIR and which install their locale files directly under
${PREFIX}/${PKGLOCALEDIR} and sort the PLIST file entries. From now
on, pkgsrc/mk/plist/plist-locale.awk will automatically handle
transforming the PLIST to refer to the correct locale directory.