ENH: update DataFrame to_latex for nicer typesetting
Is this merge-able or does it need a unit test?
 There doesn't seem to be a unit test for the to_latex method right now, but I can add one in the to_html style (comparing strings) if you'd like.

Also, I forgot to mention this requires the users to have the \usepackage{booktabs} in their latex source. So I should probably add that to the doc string.
 OK thanks. This isn't official enough functionality to be that sensitive. 
 Hi wes, I am using the to_latex method and found the \usepackage {booktabs} bug. Its harder to find with LaTeX and i was using matplotlib too. Probably missed the doc string. 
