addGrandTotals() for CompleteLister

1) rewrite of CompleteLister template
2) new method addGrandTotals() for CompleteLister
3) split some functionality to child methods, like renderTotalsRow, renderGrandTotalsRow etc.

Short test case:
```
        $model->setLimit(5, 5);
        $c = $this->add('CompleteLister');
        $c->setModel($model);

        $c->addTotals(); // totals only for limited amout of data - current "page"

        $c->addGrandTotals(); // calculate totals for all model fields, all rows
        //$c->addGrandTotals(array('StartBalance','EndBalance')); // calculate totals for only these fields
```

In CompleteLister case this is not so useful, but ... Grid extends this, so we first upgrade CompleteLister.
I'll make changes in grid template and Grid classes tonight / tomorrow.