GitLab

Added a couple of extra compile-time options for use in specialied applications; both are switched out in all standard builds.

ForceTwitter: used in combination with Twitter flag, this causes
   antitwittering to be employed irrespective of ModeFlags bit 8,
   and also irrespective of whether a window is auto-redraw or not.

HideIconBar: ensures that the icon bar is behind the backwindow, unless
   it has been brought to the front (by either method). In conjunction with
   a modified Pinboard, this can produce a quick-and-dirty iconbar-less
   machine.