localstorage modify

## Main ##
1. I had drop the fallback to cookie way , because I think this is unnecessary when web developers want  to user localstorage，but I think you can keep your insist;
2. I rewrite the data-binding , data-binding-cancel method , I add the option for forward(from model to localstorage), reverse(from localstorage to model),normal(both);

      thanks for your distribution!