If "Sort" is invoked with a selection of more than one cell in a
single column or row, and there are non-empty cells next to the
selection, a new dialog will ask if the selection should be extended
to contain those cells.
With this, a user can select only the column of data by which to sort,
and still sort the whole range.
It applies to the sort dialog as well as the "Sort Ascending" and
"Sort Descending" toolbar buttons. A specification is attached to