Plugin handling in tvserver not optimal

h4. Steps to Reproduce
1. Configure some plugin to be used
2. Stop tvservice from e.g. Task Manager Services not from TVSetup
3. Check error.log

h4. Additional Information
2009-03-14 17:44:11.351600 [5]: Exception :System.ArgumentException: Service TvEngine.Events.ITvServerEvent is not registered
   at TvLibrary.Interfaces.ServiceProvider.Get[T]()
   at TvEngine.ComSkipLauncher.Stop()
   at TvService.Service1.StopPlugins()

2009-03-14 17:44:11.367200 [5]: Exception :System.ArgumentException: Service TvEngine.Events.ITvServerEvent is not registered
   at TvLibrary.Interfaces.ServiceProvider.Get[T]()
   at TvEngine.ConflictsManager.Stop()
   at TvService.Service1.StopPlugins()