Refactor ResourceLoader, use only Texture2d in Renderer.

Source/Resources/Loaders/SoundLoader.cs

@@ -0,0 +1,15 @@
+namespace DaggerFramework
+{
+    public class SoundLoader : ResourceLoader<Sound>
+    {
+        public override Sound Load(string path)
+        {
+            // TODO
+            // var data = File.ReadAllBytes(path);
+            var sound = new Sound(path, new byte[] { });
+            sound.Path = path;
+
+            return sound;
+        }
+    }
+}