nathancremisino/FlickrLaLanne: Lack of birthday cake the secret to his longevity?We feel healthier already. Tomorrow, for his 95th birthday, locally spawned ancient fitness guru Jack LaLanne gets his very own day at John's Grill (63 Ellis at Powell). According to SF City Dish, show up to toast LaLanne with a $.95 glass of wine, which comes with a salad of Dungeness crab, seasonal greens, shrimp, avocado, mushrooms, tomato, and blue cheese dressing (available from 11 a.m. to 1:30 p.m.).Tak