De La Paz Coffee Co./FlickrThe lure of free tacos brought 'em out to El Tonayense yesterday.El Tonayense truck owner Esquivel Santana told SFoodie that Sunday's taco giveaway stunt brought out a wave of free-food junkies. The truck, which parks at Harrison and 22nd St., was part of a multi-city promo for Fox Searchlight flick (500) Days of Summer, a sensitive-slash-cute-slash-chuckly Zooey Deschanel vehicle about thwarted love. Cart vendor Crème Brulee Man was also also slated to take part in t