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/opengl2_example/main.cpp

@@ -132,6 +132,8 @@ int main(int, char**)
     ImGui_ImplOpenGL2_Shutdown();
     ImGui_ImplGlfw_Shutdown();
     ImGui::DestroyContext();
+
+    glfwDestroyWindow(window);
     glfwTerminate();
 
     return 0;