aggregate() added to DBCollection.cfc

[sjdaniels]

• uses Mongo aggregation framework
• MongoDB 2.1+ required
• fixes #31
• needs unit tests

[marcesher]

Sean, one thing I've learned about APIs like this is that it's best to not only return a subset of what the underlying driver gives you. In this case, you're returning just the results. However, I can certainly imagine legitimate situations where people would need the entire object. I'd recommend following the SearchResult and MapReduceResult approach that we're using in cfmongodb, and provide a new AggregationResult object that exposes all of what the java driver gives. In fact, you'll notice that in the existing cases, we actually return more than the Java driver... providing some convenience methods for the most common use cases

[sjdaniels]

Makes sense. I'll have a look tomorrow.