Update normalize to v2.1.3.

Reverted 69f6149489d13868ccdc3195476096c1f70499bb and 1c33b857a61c2523167a01a16e6b87fa70acdaf1 since this is a third-party file.

/CC @mdo

I could keep your custom changes, but unless there is a very specific reason to have custom changes here, there shouldn't be any since it's a third-party file.