Use different csv parser

Changed the csv parser from fast-csv to a more popular node-csv parser. This parser had an admittedly undocumented relaxed parsing mode that made it more resilient to some csv formatting issues. Without the relaxed mode turned on, it would error out on the WI feed I'm testing with, and would give line numbers, but the line numbers didn't correspond to any lines that had actual problems. So turning on the relaxed mode seemed better, and allowed it to process an unadulterated feed.

I also had to try turning on a mongoose aggregate mode that allows it to use disk for some processing, otherwise the unique id check was too large to hold in mongo's memory.

Assigning to @cap10morgan 
Ok, this one took me a while to sort out before, and again. The node-csv parser implements the stream.Transform protocol (http://nodejs.org/api/stream.html#stream_class_stream_transform), which itself means something implements the stream.Readable protocol (http://nodejs.org/api/stream.html#stream_class_stream_readable), and this is where the on "data" comes from (http://nodejs.org/api/stream.html#stream_event_data). I can't recall the winding path that brought me to this, it does seem like I should be able to use the on "row" callback instead to conform more to the node-csv library, now that I look at it, but there might have been some reason that didn't work. I'll try it one more time now that I've got some more evidence of things working and see if it does what it's supposed to do. Still, the on "data" also appears to be working and getting the correct results, one fire per row.