Time::Zone::By4D: new convenience function get_timeoffset
GPS::GpsmanData::Any: use Time::Zone::By4D::get_timeoffset
rawjsontrk2gpsman: use Time::Zone::By4D

So time offset is now always correct (using the time of the first
waypoint). Previously always the current local time offset was used.
data update (mainly updates in Rudow)
data update (minor, some new areas)
support for F:Square (Perl/Tk renderer)
F:Square currently ignored in non-edit/non-orig mode
data update (add F:Square records)
adjust test for changed data (flaechen changes)
Merge remote-tracking branch 'eserte/master' into world