Bill Maher couldn’t get so much as a chuckle out of his history professor guest tonight when the subject turned to dictators. Timothy Snyder, author of On Tyranny: Twenty Lessons From The 20th Century sat stonefaced as Maher read off a list of things about Donald Trump that remind him of Third World dictators. "Yeah, right, so I'm not going to laugh at any of that,” Snyder said on HBO’s Real Time With Bill Maher, “because in your world it's Third World dictators, but in…