Steal CSV column type inference logic from csvkit

csvkit will, for example, infer that columns with 'Y' and 'N' as values should be boolean (using `csvsql`). odo currently doesn't do that. It also knows lots of dialects.

I'm building a conda package for csvkit right now for python3, @asmeurer already built one that's in his channel on binstar. You can just look in my binstar channel (same as davclark), or nudge me. It's not there yet.