question: why package automatically call toArray on agregation

Hi @sakulstra,

thank you for your fork.
I would like to ask, why you call `toArray()` on returned aggregation?
https://github.com/sakulstra/meteor-aggregate/blob/master/index.js#L14

In the original code, only the cursor was returned, and then it was up to user to call `toArray()`
https://github.com/meteorhacks/meteor-aggregate/blob/master/index.js#L11