Some changes to the YnDialog widget used when popup_dialog is On.
If a button is labelled with a space, it just looks like an
unlabelled button. Switch to "Spc" for space, "Ent" for \n and
"Ret" for \r. (The last two aren't completely logical but I
haven't seen any dialogs that need them and they'll be better
than "^J" and "^M" if there are such.)
For yn#aq dialogs, preload a grayed-out "#" in the count widget.
Just for show; has no tangible effect.
The count widget should return long rather than plain int.