Broken ANSI;  a bit more objectiness

-- output now filters through ANSI plugin.  Currently it'll just remove
all ANSI codes.  That's not right, is it?
-- input focuses itself at start time;  output will redirect focus to
input.
-- skeleton of 'theme' support.
Work toward having actual preferences.

-- stubbed-out Prefs Editor
-- Prefs singleton class
-- font picked from (hard-coded) prefs.