[Patch] new feature: sort labels

[Andre Poenitz]

The patch attached sorts lables alphanumerically. This is nice uif you have
a hundred of them and stick to the 'sec:*', 'eq:*' naming convention.

It's a new feature though.

Ok to apply anyway?


---

Related question: Would it be ok to change the functions

  vector<string> getLabelList() const

into something like

  void fillLabelList(vector<string> &) const

This would reduce the need to return dummy empty label lists in some cases
and the code in buffer.C would be slightly simpler (i.e. instead of

  vector<string> getLabelList() const
  {
    vector<string> label_list;
    for (inset_iterator it = inset_const_iterator_begin();
         it != inset_const_iterator_end(); ++it) {
      vector<string> const l = it->getLabelList();
      label_list.insert(label_list.end(), l.begin(), l.end());
    }
    return label_list;
  }

we'd have

  void fillLabelList(vector<string> & label_list) const
  {
    for (inset_iterator it = inset_const_iterator_begin();
         it != inset_const_iterator_end(); ++it)
      it->fillLabelList(label_list);
  }


Andre'


-- 
Those who desire to give up Freedom in order to gain Security,
will not have, nor do they deserve, either one. (T. Jefferson)