Not all heroes wear capes. Some wear helmets, others stethoscopes. But some kind-hearted heroes work behind a bar, wielding rags and working for tips. We all know that bartenders have hard jobs. Wrangling drunks and scrambling for tiny tips isn't easy. But we don't often talk about the way bartenders look out for their clientele, whether they're offering an ear to a troubled person, or protecting women from creepy patrons. Twitter user @guttersnipe tweeted about the latter situation this week,…