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.HLE/Gpu/Texture/LinearSwizzle.cs

@@ -0,0 +1,19 @@
+namespace Ryujinx.HLE.Gpu.Texture
+{
+    class LinearSwizzle : ISwizzle
+    {
+        private int Pitch;
+        private int Bpp;
+
+        public LinearSwizzle(int Pitch, int Bpp)
+        {
+            this.Pitch = Pitch;
+            this.Bpp   = Bpp;
+        }
+
+        public int GetSwizzleOffset(int X, int Y)
+        {
+            return X * Bpp + Y * Pitch;
+        }
+    }
+}