* data update (u.a. some changes in Karlshorst)
* moved temp_blockings_tasks task bbd_to_existsid into own file

  This task was not temp blockings-specific anymore. It's now
  an own script named bbd_to_sourceid_exists.
* new: bbd_to_osm_watch_list
* new Makefile target for creating osm_watch_list*
* data update (systematically added osm_watch directives from
  old bbbike-aux file)
* bbd_to_osm_watch_list: error checking
* MerkaartorPlugin: always use the currently visible region
* data update