OSM link: use openstreetmap.org instead of openstreetmap.de

openstreetmap.de is now available via the context menu.
minor BBBikeOsmUtil improvements

* seamark:* is now regarded as "uninteresting" tag
* handle also disused=yes (normally it should railway=disused or
  highway=disused, but there is still some legacy around)
* don't render aerial_view items
* items with boundary tag are never rendered as areas, but as closed
  lines now
data update
data update (u.a.: remove pedestrian bridge Ostkreuz, more Bordstein
fragezeichen entries)