Improvements to audout (#58)

* Some audout refactoring and improvements

* More audio improvements

* Change ReadAsciiString to use long for the Size, avoids some casting

Ryujinx.Core/Settings/SystemSettings.cs

@@ -1,6 +1,6 @@
 namespace Ryujinx.Core.Settings
 {
-    public class SetSys
+    public class SystemSettings
     {
         public ColorSet ThemeColor;
     }