Implement plugin restore after daemon restart

This ensures that:

- The in-memory plugin store is populated with all the plugins
- Plugins which were active before daemon restart are active after.
  This utilizes the liverestore feature when available, otherwise it
  manually starts the plugin.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Upstream-commit: dfd91873056c172ffc061d882da0cd18204b521a
Component: engine

components/engine/plugin/manager_windows.go

@@ -19,3 +19,7 @@ func (pm *Manager) initSpec(p *plugin) (*specs.Spec, error) {
 func (pm *Manager) disable(p *plugin) error {
 	return fmt.Errorf("Not implemented")
 }
+
+func (pm *Manager) restore(p *plugin) error {
+	return fmt.Errorf("Not implemented")
+}