* test case for a "Search again with nearest node" problem

  The problem is somewhat tricky: the search needs to have
  pref_fragezeichen turned on, and both start and goal coordinate have
  to be part of the fragezeichen net, but outside of scope=city. In
  this case, adjust_scope_for_search() does not need to adjust the
  scope to region, and the subsequent search fails. Actually it does
  not fail completely, but the best node found so far is adjusted as
  the new goal node, which is far away from the real one.

  For the test case fragezeichen and landstrassen have now non-empty
  files in data-test, and the "berlin" file with the city borders is
  copied from the original data directory.
* fix for a special "Search again with nearest node" problem

  This is fixing the new test case in the previous commit.