implement comparator more correct, so, we can get rid of skipSeal flag for std classes

js/js.translator/testFiles/kotlin_lib.js

@@ -306,10 +306,15 @@ var kotlin = {set:function (receiver, key, value) {
         }
     );
 
+    var ComparatorImpl = Kotlin.$createClass(Kotlin.Comparator, {
+                                                 initialize: function (comparator) {
+                                                     this.compare = comparator;
+                                                 }
+                                             }
+    );
+
     Kotlin.comparator = function (f) {
-        var result = Kotlin.$new(Kotlin.Comparator)();
-        result.compare = f;
-        return result;
+        return Kotlin.$new(ComparatorImpl)(f);
     };
 
     Kotlin.collectionsMax = function (col, comp) {

js/js.translator/testFiles/kotlin_lib_ecma5.js

@@ -66,9 +66,8 @@ var Kotlin = {};
                 if (initializer != null) {
                     initializer.apply(o, arguments);
                 }
-                if (initializer == null || !initializer.hasOwnProperty("skipSeal")) {
-                    Object.seal(o);
-                }
+
+                Object.seal(o);
                 return o;
             };
         }
@@ -164,10 +163,6 @@ var Kotlin = {};
             }
         }
 
-        if (initializer) {
-            Object.defineProperty(initializer, "skipSeal", {value: true});
-        }
-
         return Kotlin.createClass(parent || null, initializer, descriptors);
     };