Changes since tag v1.6.1

commit 9329d0c1842f77d1843f9e64338d19df57ad1039
Author: Hendrik Leppkes <h.leppkes@gmail.com>
Date:   Tue Jul 2 14:34:11 2019 +0200

    Fixed zone discovery logic
    
    Instead of reading all possible zones from HBD, only discover zones
    which are actually on the worldmap, since thats where Routes should be
    used.

