[Bug] [21.4] Custom buffers missing lotsa buttons

[Stephen J. Turnbull]

Didier Verna writes:

 > That's with the latest CVS XEmacs 21.4 and packages. My Custom buffers
 > are missing a lot of buttons under X11.

IIRC this is an oldy.  ISTR Andy replaced the grody manually
constructed XPixmap buttons with spiffy native widgets, but left no
fallbacks for non-widget builds.  reconfigure with --with-widgets to
work around.