Add timeout flag for container start times

This currently depends on a runc PR:

https://github.com/opencontainers/runc/pull/703

We need this pr because we have to SIGKILL runc and the container root
dir will still be left around.

As for the containerd changes this adds a flag to containerd so that you
can configure the timeout without any more code changes.  It also adds
better handling in the error cases and will kill the containerd-shim and
runc ( as well as the user process if it exists ) if the timeout is hit.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

supervisor/create.go

@@ -29,6 +29,7 @@ func (s *Supervisor) start(t *StartTask) error {
 		RuntimeArgs: s.runtimeArgs,
 		Labels:      t.Labels,
 		NoPivotRoot: t.NoPivotRoot,
+		Timeout:     s.timeout,
 	})
 	if err != nil {
 		return err