xplanetFX 2.0.21 & 2.0.22: czech and dutch language, bugfixes

Version 2.0.22:
* Added dutch language file - thanks to Tim van der Kodde!
* Added czech language file - thanks to Martin Pavlík!

Version 2.0.21:
* Daemon renders to a interim file in the cache first which is copied to the
  final destination afterwards (instead of working on the final image. Looks
  better when xplanetFX got killed while rendering and hopefully ends the bug
  'black wallpaper on first start')
* Names of final images in ./output changed to xplanetFXn.png
* changed default configuration to lon:0, lat:0, showorbit:1, orbit:-60
* Bug in default configuration of GUI: SEARCHMAPURL was missing in dictionary
  _DEFAULT_SETTINGS
* Bug in dameon: render to file failed after cleanup in 2.0.20