Made the default buttons on the dialog active and focused upon the
dialog appearence.
Bound 'Escape' and 'Return' keys to the dialog dismissal where it
was appropriate: mainly for dialogs with only one button and no
editable fields, but on console output dialogs as well.
Signed-off-by: Eygene Ryabinkin <rea-git@codelabs.ru> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>