Plugins fix and Multithreading change.

Look for plugins dependecies in current AppDomain.
PluginManager.OnStreamUpdate() now works synchronously instead of using Task.Factory .
OnlineRadio.Core.Radio now uses Task.Factory instead of old Being/End Invoke pattern .
Working Audio Plugin

Thanks to NAudio, AudioPlugin now plays the IceCast stream. Proof of concept is done and over.