Refactoring and cleanup of GLInterface (now GLContext)

Source/UnitTests/StubHost.cpp

@@ -8,7 +8,6 @@
 #include <memory>
 #include <string>
 
-#include "Common/GL/GLInterfaceBase.h"
 #include "Core/Host.h"
 
 void Host_NotifyMapLoaded()
@@ -54,7 +53,3 @@ void Host_YieldToUI()
 void Host_UpdateProgressDialog(const char* caption, int position, int total)
 {
 }
-std::unique_ptr<cInterfaceBase> HostGL_CreateGLInterface()
-{
-  return nullptr;
-}