Prepare startContainer() to have more action

Currently startContainer() is used to create and to run a container.
In the next patch it will be used to restore a container.

Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

run.go

@@ -73,7 +73,7 @@ command(s) that get executed on start, edit the args parameter of the spec. See
 		if err != nil {
 			return err
 		}
-		status, err := startContainer(context, spec, false)
+		status, err := startContainer(context, spec, CT_ACT_RUN, nil)
 		if err == nil {
 			// exit with the container's exit status so any external supervisor is
 			// notified of the exit with the correct exit status.