[PATCH] some sizing fixes in the x11 terminal

[Dima K. <gn...@di...>]

I'm attaching a patch to fix some sizing errors that were introduced by
some of my earlier X11 fixes. These were mostly confusion between height
and gheight. An observable problem that this patch fixes is plotting
something, and then doing a replot. With the same data file the replot
shouldn't have any visible effects, but there was some geometric
shifting as a result of the errors.