* check source files for license header
Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

* tweak
Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

* add license header to all relevant source files
Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>