Small OpenGL Renderer refactoring (#177)

* Call OpenGL functions directly, remove the pfifo thread, some refactoring

* Fix PerformanceStatistics calculating the wrong host fps, remove wait event on PFIFO as this wasn't exactly was causing the freezes (may replace with an exception later)

* Organized the Gpu folder a bit more, renamed a few things, address PR feedback

* Make PerformanceStatistics thread safe

* Remove unused constant

* Use unlimited update rate for better pref

Ryujinx.Graphics/Gal/IGalFrameBuffer.cs

@@ -0,0 +1,27 @@
+using System;
+
+namespace Ryujinx.Graphics.Gal
+{
+    public interface IGalFrameBuffer
+    {
+        void Create(long Key, int Width, int Height);
+
+        void Bind(long Key);
+
+        void BindTexture(long Key, int Index);
+
+        void Set(long Key);
+
+        void Set(byte[] Data, int Width, int Height);
+
+        void SetTransform(float SX, float SY, float Rotate, float TX, float TY);
+
+        void SetWindowSize(int Width, int Height);
+
+        void SetViewport(int X, int Y, int Width, int Height);
+
+        void Render();
+
+        void GetBufferData(long Key, Action<byte[]> Callback);
+    }
+}