#48 extent bug with rotated group

[Scott Johnston]

The computation of a composite-graphics extent (group)
has a bug when the group or one of its members is
rotated. You can see this by creating a large polygon,
grouping it with a small graphic that overlays it, then
rotating the combination. The only time the bounding
box (represented by the selection handles) shrinks to
the right size is when the degrees of rotation is 0
(and maybe 180).