Bug 1032629 - APN Settings UX refresh

https://bugzilla.mozilla.org/show_bug.cgi?id=1032629
We use `JSON.parse(JSON.stringify())` in so many different places but it looks like we just want to create a copied object. In this way, why not just use `var apnCopy = _cloneApn(apn)` in `apn_utils` or `var apnCopy = Object.create(apn)` ?