Hi there,

I've found several minor issues in Tkinter.Listbox which are all fixed
by the attached patch.

I'm considering the bbox method should be clear in relation to the
amount of accepted arguments, which is always one. So I dropped the
*args usage there.
The curselection method has a reminder about applying getints on it, I
have done it now. I think it is fine to finally fix it, since we have
some tests for it now (at least in the tk_and_idle_maintenance branch).
The remaining changes in the patch are all about fixing docstring of
several methods in Listbox.