However, rectangles in Matlab are fully fledged objects rather than a
patch wrapped in an hggroup. Frankly I don't see what that adds for
Matlab to do it that way. In any case, I needed to keep compatibility
with Octave 3.4.0, so adding a new type of graphic handle didn't seem
the best thing.
I attach my implementation of rectangle here. Should I commit it, or
should we go the Matlab way and make rectangles full objects?