A more (or less, depending in pov :-) aggressiv hacker. Compared
to super, it dispatches less events to address open issues.
Issue #474-swingx: double click should start edit (not expand/collapse)
changed mightBeExpansionTrigger to filter out clickCounts > 1
Issue #875-swingx: cell selection mode
changed the dispatch to do so only if mouse event outside content
box and leading
Issue #1169-swingx: remove 1.5 dnd hack
removed the additional dispatch here and
changed in the implementation of hackAroundDragEnabled
to no longer look for the system property (it's useless even if set)