Promotions for new TV shows often involve an endless series of TV ads and not much more. NBC may have broken the mold with its upcoming series “Undateable” by sending the stars of the show on a multi-city, cross-country comedy tour. The “Undateable Comedy Tour” stopped in Boston Monday evening. The tour is being led by the show’s co-creator and executive producer Bill Lawrence, whose TV comedy credits include “Scrubs,” “Spin City,” and “Cougar Town.” Lawrence was joined by “Undateable” stars Chris D’Elia, Brent Morin, Ron Funches (above), and Rick Glassman, all of whom are stand-up comedians. With Lawrence acting as host, each cast member performed a stand-up set aimed at giving audiences a glimpse at the type of humor they’ll see when “Undateable” premieres later this year on NBC.