Are IncidenceEditor's CategoryDialog, CategoryEditDialog, and CategorySelectDialog unused?

[Glen Ditchfield]

 IncidenceEditor defines three dialogs:  CategoryDialog, CategoryEditDialog, 
and CategorySelectDialog.  I haven't found any place where they are used, 
though.  Are they left-overs from earlier days, or am I just not looking in 
the right places?

None of the three are declared with INCIDENCEEDITOR_EXPORT.  Does that mean 
they can be deleted?