Add gpl header in *.h files
- Move helper scripts into a dedicated folder
- '\n' ich echo string needs option -e
- Scripts can now executed from an arbitrary directory. It's no longer
  necessary that the current working dir (pwd) is directory where the
  scripts are located
Add a commend to each #endif to see where it belongs to
Merge pull request #12 from alexander-zimmermann/master

GPL Header; Moving scripts