Run new topic through parser when it is updated

Fixes #584

client/js/shout.js

@@ -342,9 +342,8 @@ $(function() {
 	});
 
 	socket.on("topic", function(data) {
-		// .text() escapes HTML but not quotes. That only matters with text inside attributes.
 		var topic = $("#chan-" + data.chan).find(".header .topic");
-		topic.text(data.topic);
+		topic.html(Handlebars.helpers.parse(data.topic));
 		// .attr() is safe escape-wise but consider the capabilities of the attribute
 		topic.attr("title", data.topic);
 	});