The redraw-on-every-delete-or-delete-like-command aspect of
the current code isn't great, but it's hard to get much
better.  Later, I will make it only redraw when the cursor
is near the beginning or the end of the bbox.

Now testing a fix for the autoscrollbar bit as well.

I finally got around to fixing the
entry-expansion-on-wrapped-lines problem.  A fix is in testing.

Also, I investigated the "auto -x" stuff a while ago, and it
looks like an internal Tix problem (feature?).  Bizarre.  I
was just about to mark this as WONTFIX, but I remembered how
bbox helped me solve the entry handling problem.  I'll be we
could manually add/remove the scrollbar at the right times
using bbox.

Entry behavior has another problem which is it doesn't
recognize wrapping.  Thus, a one-line message that wraps
gets counted as a one-line message even if it takes up more
space visually.

The option 'auto-y' is really spelled 'auto -x'.  However,
Tix doesn't seem to be accepting this, so I have opted for
'y' instead.  Perhaps we will fix this at some point.

Entry behavior has been improved.  Scrollbar coming soon.

There should be a vertical scrollbar when necessary (auto-y?
Probably no such option).  It would be nice if it were
hidden until necessary.

Also, the entry hiding makes the text jump when it is
packed/unpacked.  That is undesirable.  Additionally, when
you type more text and the entry expands, the text does not
rescroll.

I think that the entry should be an addition to the window,
not part of it (i.e. should make the window grow)