OGL: implement bounding box support with ssbo

This implemention tries to be as accurate as the old SW implemention, but it will remove the dependcy of our vertexloader on videosw.

Source/Core/VideoBackends/OGL/BoundingBox.h

@@ -0,0 +1,20 @@
+// Copyright 2014 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+namespace OGL
+{
+
+class BoundingBox
+{
+public:
+	static void Init();
+	static void Shutdown();
+
+	static void Set(int index, int value);
+	static int Get(int index);
+};
+
+};