Add sqlite specific option

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>
Add method to access defined commandline options

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>
Make sqlite file required for sqlite

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>
Fix unittests

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>