"She lint rolled me," delights Harry, a jingle composer who's made a mint on a burger commercial, while reveling in how his shedding Labrador unwittingly played matchmaker for him and Louise, a Broadway chorus girl.In Darling Grenadine, a big-hearted and surprisingly tender if sometimes manipulative musical, it's only a matter of time before this mutt-assisted couple who meets cute runs headlong into hurdles. That goes with any new romance. But these two face the sort of giant game-changer that...