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/OsHle/Services/Aud/AudioOutData.cs

@@ -0,0 +1,14 @@
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Core.OsHle.IpcServices.Aud
+{
+    [StructLayout(LayoutKind.Sequential)]
+    struct AudioOutData
+    {
+        public long NextBufferPtr;
+        public long SampleBufferPtr;
+        public long SampleBufferCapacity;
+        public long SampleBufferSize;
+        public long SampleBufferInnerOffset;
+    }
+}