Sets references to elements inside the component.
@private
function(el, id) {
        var me = this,
            childEls = me.getChildEls(),
            baseId, childName, i, selector, value;

        baseId = (id || me.id) + '-';
        for (i = childEls.length; i--; ) {
            childName = childEls[i];

            if (typeof childName == 'string') {
                // We don't use Ext.get because that is 3x (or more) slower on IE6-8. Since
                // we know the el's are children of our el we use getById instead:
                value = el.getById(baseId + childName);
            } else {
                if ((selector = childName.select)) {
                    value = Ext.select(selector, true, el.dom); // a CompositeElement
                } else if ((selector = childName.selectNode)) {
                    value = Ext.get(Ext.DomQuery.selectNode(selector, el.dom));
                } else {
                    // see above re:getById...
                    value = el.getById(childName.id || (baseId + childName.itemId));
                }

                childName = childName.name;
            }

            me[childName] = value;
        }
    }