Edit localized in-app product names (bug 1070120)

W.I.P. - DO NOT MERGE

This allows devs to edit localizations for in-app product names. They can select a language in edit mode and the text field will switch to that language. What's missing is you can't set the default locale for each product. I think we probably need that before landing this patch.

![screen shot 2014-09-29 at 5 30 47 pm](https://cloud.githubusercontent.com/assets/55398/4450772/c5a3f652-4829-11e4-9f27-60c5c7926ede.png)