Merge branch 'master' into viewport

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/opengl2_example/imgui_impl_glfw_gl2.cpp
#	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
#	examples/vulkan_example/main.cpp
#	imgui.h

examples/directx10_example/main.cpp

@@ -224,6 +224,7 @@ int main(int, char**)
     ImGui::DestroyContext();
 
     CleanupDeviceD3D();
+    DestroyWindow(hwnd);
     UnregisterClass(_T("ImGui Example"), wc.hInstance);
 
     return 0;