Commentary on the previous work:
That was a goodie because I don't anticipate we'd want to put it in
the mainline image; it's mostly an exploration of layout, morphs, and
scrollbars.  I did need the functionality, however.

Discoveries:
ScrollBar tracks values mostly in fractions between 0 and 1.
ScrollPane's mostly use pixels.

I was having trouble getting this to work with scrollbars because the
original RBScrollLayout code was
layout: aMorph in: newBounds
	"Compute the layout for the given morph based on the new
	bounds"
	"transformmorph's didn't expect to do layout, so don't
	transform"
	aMorph scroller doLayoutIn: 
	       (aMorph scroller transform globalBoundsToLocal:
	       newBounds).
Every time I scrolled this repositioned the material inside the
scrollpane, keeping the left hand edge always in view.  (Well, not
always, but I didn't look into why.  Sometimes clicking on the arrows
would work to move the image in the scrollpane).

RB = Ross Boylan, not Refactoring Browser, in the changeset.

This was in a 3.6 image; later images support two way scrolling with
the basic ScrollPane rather than TwoWayScrollPane.