Remove windows code and simplify linux

Windows will not use containerd and its just unused code and unneed
complexity to keep it all around.

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

supervisor/supervisor.go

@@ -345,3 +345,41 @@ func (s *Supervisor) restore() error {
 	}
 	return nil
 }
+
+func (s *Supervisor) handleTask(i Task) {
+	var err error
+	switch t := i.(type) {
+	case *AddProcessTask:
+		err = s.addProcess(t)
+	case *CreateCheckpointTask:
+		err = s.createCheckpoint(t)
+	case *DeleteCheckpointTask:
+		err = s.deleteCheckpoint(t)
+	case *StartTask:
+		err = s.start(t)
+	case *DeleteTask:
+		err = s.delete(t)
+	case *ExitTask:
+		err = s.exit(t)
+	case *ExecExitTask:
+		err = s.execExit(t)
+	case *GetContainersTask:
+		err = s.getContainers(t)
+	case *SignalTask:
+		err = s.signal(t)
+	case *StatsTask:
+		err = s.stats(t)
+	case *UpdateTask:
+		err = s.updateContainer(t)
+	case *UpdateProcessTask:
+		err = s.updateProcess(t)
+	case *OOMTask:
+		err = s.oom(t)
+	default:
+		err = ErrUnknownTask
+	}
+	if err != errDeferredResponse {
+		i.ErrorCh() <- err
+		close(i.ErrorCh())
+	}
+}