Fix the threading for GL Context in Qt5.

Connect the emu_thread start/finish to a moveContext slot.

src/video_core/video_core.cpp

@@ -36,7 +36,6 @@ void Init(EmuWindow* emu_window) {
     glewExperimental = GL_TRUE;
 
     g_emu_window = emu_window;
-    g_emu_window->MakeCurrent();
     g_renderer = new RendererOpenGL();
     g_renderer->SetWindow(g_emu_window);
     g_renderer->Init();