Implement basic CSV parsing and import.

This implements basic CSV parsing and import features, as well as fixes a few bugs in the original code. The CSV file currently expects fields for both locations and events, and are not yet configurable. A correct CSV line should look as follows:

```csv
venue_id,"Venue Name","Venue Street Address","Venue Extended Address","Venue City","Venue State","Venue Postal Code","Venue Country Code","Venue Web Address","Venue Description",event_id,venue_id,"Event Name","Event Status","Event MySQL-Formatted Start Date and Time","Event MySQL-Formatted End Date and Time","Event Web Address","Event Description"
```

To interpret null values to the database, they should be escaped as `\N` (case sensitive) in the CSV file. For instance:

```csv
27,"Spot Coffee Elmwood","765 Elmwood Ave.",\N,"Buffalo","NY","14222","United States","http://www.spotcoffee.com/",\N,259,27,"Melscamp: Exploding Chaos","active","2013-08-04 00:00:00",\N,"http://infringebuffalo.org/show.php?id=1417",\N
```