STYLE: revert bitSet/HashSet setMany() to set() method (issue #837)

- improves backward compatibility and more naming consistency.
  Retain setMany(iter1, iter2) to avoid ambiguity with the
  PackedList::set(index, value) method.

applications/utilities/parallelProcessing/reconstructPar/reconstructPar.C

@@ -186,7 +186,7 @@ int main(int argc, char *argv[])
         wordHashSet names;
         forAllConstIters(rp, iter)
         {
-            names.insertMany(iter.object());
+            names.insert(iter.object());
         }
 
         regionNames = names.sortedToc();