Avoid duplicates in Observables list

config/jsdoc/api/plugins/observable.js

@@ -41,7 +41,7 @@ exports.handlers = {
           cls.observables = [];
         }
         observable = observables[doclet.observable];
-        if (cls.observables.indexOf(observable) == -1) {
+        if (observable.type && cls.observables.indexOf(observable) == -1) {
           cls.observables.push(observable);
         }
         if (!cls.fires) {

config/jsdoc/api/template/tmpl/observables.tmpl

@@ -16,8 +16,10 @@
   <tbody>
   <?js
       var self = this;
+      var propsByName = {};
       props.forEach(function(prop) {
-        if (!prop) { return; }
+        if (!prop || propsByName[prop.name]) { return; }
+        propsByName[prop.name] = prop;
         var setter = prop.readonly ? 'no' : 'yes';
   ?>