python: expose also platform.*.Application.dpi_scaling.

For some reason only window and framebuffer size was exposed but not
this. Made DPI-aware calculations impossible to do.

doc/python/pages/changelog.rst

@@ -96,6 +96,8 @@ Changelog
     to make the window resizable on startup
 -   Exposed :ref:`platform.sdl2.Application.exit_event` and
     :ref:`platform.glfw.Application.exit_event`
+-   Exposed :ref:`platform.sdl2.Application.dpi_scaling` and
+    :ref:`platform.glfw.Application.dpi_scaling`
 -   Exposed :ref:`platform.glfw.Application.swap_interval` and
     :ref:`platform.glfw.Application.main_loop_iteration`
 -   Exposed a basic interface of :ref:`trade.AbstractImageConverter` and

src/python/magnum/platform/application.h

@@ -85,6 +85,7 @@ template<class T, class Trampoline, class Holder> void application(py::class_<T,
         .def("redraw", &T::redraw, "Redraw immediately")
         .def_property_readonly("window_size", &T::windowSize, "Window size")
         .def_property_readonly("framebuffer_size", &T::framebufferSize, "Framebuffer size")
+        .def_property_readonly("dpi_scaling", static_cast<Vector2(T::*)() const>(&T::dpiScaling), "DPI scaling")
         /* Event handlers */
         .def("exit_event", &T::exitEvent, "Exit event")
         .def("viewport_event", &T::viewportEvent, "Viewport event")