title: mongodb to return object from facet
body: <p>Is it possible to have facet to return as an object instead of an array? It seems a bit counter intuitive to need to access <code>result[0].total</code> instead of just <code>result.total</code></p>
  
  <p>code (using mongoose):</p>
  
  <pre><code>        Model
              .aggregate()
              .match({
                  "name": { "$regex": name },
                  "user_id": ObjectId(req.session.user.id),
                  "_id": { "$nin": except }
              })
              .facet({
                  "results": [
                      { "$skip": start },
                      { "$limit": finish },
                      {
                          "$project": {
                              "map_levels": 0,
                              "template": 0
                          }
                      }
                  ],
                  "total": [
                      { "$count": "total" },
                  ]
              })
              .exec() 
  </code></pre>