We’ll try not to read too much into this mural: The Trader Joe’s in Boston. Photo courtesy of atomicity via Flickr Before you head over to Trader Joe's to stock up on cheap snacks for your Labor Day weekend festivities, stop and consider shopping somewhere else. Labor Day was enacted not as a general holiday to rest in honor of laborers, but in response to the tragic deaths of striking workers. And good old cheap Joe -- which just agreed to stop selling eggs from Jack DeCoster's vile operations -- is one of the remaining holdouts in this decade's most …