Return null as state for stateless actions

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
ctl: add action-state command

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Minor code clean-up

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>