Overview Data Table Sort incl. Files

.. when sorting the table we sorted all the columns that are
   visible to the user, but not the associated filenames
   that are used by clickthru, so clickthru would jump to the
   wrong activity.

src/Charts/OverviewItems.cpp

@@ -1147,6 +1147,17 @@ DataOverviewItem::sort(int column, Qt::SortOrder order)
     // phew!
     values = ordered;
 
+    // don't forget the filenames used in clickthru
+    if (files.count()) {
+        QVector<QString> newfiles = files;
+
+        // resequence
+        for(int k=0; k<argsortindex.count() && k < newfiles.count(); k++)
+            newfiles[k] = files[argsortindex[k]];
+
+        files = newfiles;
+    }
+
     lastsort = column;
     lastorder = order;
 }