added i18n support for ngPluralize

transparently localize ngPluralize directives by translating the value
of the "when"-attribute before ngPluralize compiles it

app/js/i18n.js

@@ -128,6 +128,18 @@ angular.module('myApp.i18n', ['izhukov.utils'])
     return _;
   }])
 
+  .directive('ngPluralize', ['_', function(_) {
+    return {
+      restrict: 'EA',
+      priority: 1, // execute before built-in ngPluralize
+      compile: function(element) {
+        var msgid = element.attr('when');
+        var msgstr = _(msgid);
+        element.attr('when', msgstr);
+      }
+    }
+  }])
+
   .directive('myI18n', ['_', function(_) {
     return {
       restrict: 'EA',