Make most subsystems available as protected properties in base Game class, implement IDisposable on systems.

Voile/Source/Audio/FmodAudioBackend.cs

@@ -71,6 +71,11 @@ namespace Voile.Audio
             channelGroup.addDSP(0, dsp);
         }
 
+        protected override void Shutdown()
+        {
+
+        }
+
         private DSP CreateReverbDsp(AudioEffectReverb effectReverb)
         {
             DSP dsp;
@@ -122,11 +127,6 @@ namespace Voile.Audio
             return _channelGroups[busName];
         }
 
-        public override void Shutdown()
-        {
-
-        }
-
         private FMOD.System _system;
 
         // TODO: use a different key for the dictionary, paths are not good :( (waste of memory lol)