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/NvGpuFifoMeth.cs

@@ -1,11 +0,0 @@
-namespace Ryujinx.HLE.Gpu
-{
-    enum NvGpuFifoMeth
-    {
-        BindChannel           = 0,
-        SetMacroUploadAddress = 0x45,
-        SendMacroCodeData     = 0x46,
-        SetMacroBindingIndex  = 0x47,
-        BindMacro             = 0x48
-    }
-}