Second) fix the calendar and other

[theavege]

No description provided.

[theavege]

@MoAlyousef, Please accept the PR.

[MoAlyousef]

I have an issue with the App::default().run() construct at the end of main.
Although it works in many examples, not doing so might cause some failures:

• FLTK's registering of image types for SharedImage require such initialization before any WidgetExt::set_image call is made.
• Similarly the FrameTypes which FLTK initializes at call time, fltk-rs can't do so, so it does it at initialization time.
• High dpi on macos retina displays, requires it to be called before calling window creation code.