* cgi: prepared <link rel> for opensearch description

  But not yet activated, the keyword support needs to be much better.
  Especially it should be possible to accept street names with spaces.
* data update (amongst other things changed some borders within Spandau,
  see Amtsblatt 11/2013)
* inc'd to version 3.18
* fixed some URLs in BBBikeVar.pm
* modernized README files (new version, fixed URLs, removed some
  obsolete or non-working sections, fixed some wordings...)
* regenerated html variants
* date for 3.18