Delta values now work for non-numerical values. Any column,
when its value differs from its ref, becomes orange.
A column that was already a "delta column" keeps its previous
behavior (dupe cells for these columns are always displayed in
orange).
Sorting behavior, when Dupes Only and Delta Values are enabled
at the same time, has also been extended to non-numerical
values, making it easy to mass-mark dupe rows with orange
values.
Documentation was updated, unit tests were added.
Fixes#213
Because the latest changes in hscommon include the introduction of a base GUIObject which significantly changes view setting mechanisms, significant adjustments had to be made in dupeGuru.
