How big of a deal are doggie politics to D.C. residents? Big enough to cause D.C. Mayor Adrian Fenty and Ward 2 Council member Jack Evans to show up for the groundbreaking at the new S Street Dog Park. Flickr user maxedaperture stopped by the ceremony yesterday and snagged a few good shots. The triangle park at 17th and S Streets NW had been an unofficial dog park for years, and the city finally approved…