Refactoring for speed and debug capability

Here are the changes I was proposing in #15. It's a bit messier than I prefer, but I think it works fine. The YAML files need fixing in some cases. 1_tables wasn't always 0-indexed, and I suspect there are similar issues with the others. Not thoroughly tested, but it seems to work fine with the tables file once it was modified. Much faster.

Oh, and I couldn't get csvkit to work, so I just used csv, which means that if we hit unicode, we will have troubles. I don't think we will, but even so, something to bring back. I just ran out of time for this afternoon.