Is there a way to populate ***all*** fields when running a mongoose query, in case you don't know in advance which fields are the referenced documents? Something like this:

```
schema = new Schema({ ref: {type:ObjectId, ref:'ref'}});
db = Model('data', schema);

db.find({}).populate('*').
// or
db.find({}).populate({path:'*'}).

//=> {ref: {_id:...,}} // "ref" is populated automatically

```