Low level graphics API prerequisites (#319)

* Add GalPipelineState and IGalPipeline

* Separate UploadVertex call

* Add ConstBuffer cache

* Move Vertex Assembly into GalPipelineState

* Move Uniform binds to GalPipelineState

* Move framebuffer flip into a buffer

* Rebase

* Fix regression

* Move clear values from VertexEndGl to ClearBuffers

* Rename obscure names O->Old S->New

Ryujinx.Graphics/Gal/IGalPipeline.cs

@@ -0,0 +1,7 @@
+namespace Ryujinx.Graphics.Gal
+{
+    public interface IGalPipeline
+    {
+        void Bind(GalPipelineState State);
+    }
+}