update orders to load extended javascript features first

[Li Xu]

Hi, all

I noticed that extended javascript features is always loaded first than
default javascript features.
This is okay for normal case. However if we'd like an extended feature to
overwrite an default feature, this would become a problem.
Is there any objection to update the order to load default feature first?

 protected List<String>
defaultFeatures(@Named("shindig.features.default")String features,

@Named("org.apache.shindig.features-extended")Set<String> extended) {
    /*return ImmutableList.<String>builder()
        .addAll(extended)
        .addAll(Splitter.on(',').split(features))
        .build();*/
    return ImmutableList.<String>builder()
    .addAll(Splitter.on(',').split(features))
    .addAll(extended)
    .build();
  }

thanks,
li