🚀 go-pugleaf

	I am building the class PushButton (just as an exercise) using
3.0 classes only, derived from class Button. I just want a button with a
label inside. The constructor would be declared something like:

    PushButton(const char *s, Font *f, Color *fg, Color *bg, Action *a);

	The telltale for the Button would be built inside this constructor,
however, Button parent class requires the telltale before I can build it.
I know I can pass nil to Button constructor and set it later because telltale_
is protected, not private, but then listener_ would be initialized whith a nil
Glyph. Can someone tell me how could this be done?

	Thanks.

	    Juan