fix: Allow setAnnotations to use custom className

Make setAnnotations could use custom className

#4362 from FavorMylikes/patch-1

Author: andrewnester

lib/ace/layer/gutter.js

@@ -93,7 +93,10 @@ var Gutter = function(parentEl) {
                 rowInfo.text.push(annoText);
 
             var type = annotation.type;
-            if (type == "error")
+            var className = annotation.className;
+            if (className) 
+                rowInfo.className = className;
+            else if (type == "error")
                 rowInfo.className = " ace_error";
             else if (type == "warning" && rowInfo.className != " ace_error")
                 rowInfo.className = " ace_warning";