Edit packaged app features on the version edit page, rather than the app listing page (bug 877284)

# Packaged App
![packaged_edit](https://f.cloud.github.com/assets/23885/634210/be5d7874-d213-11e2-8224-a8b70235a28c.png)

# Hosted App
![hosted_edit](https://f.cloud.github.com/assets/23885/634211/be7193ea-d213-11e2-965c-9e24bb71be0b.png)
![hosted_view](https://f.cloud.github.com/assets/23885/634212/be7fded2-d213-11e2-8ca1-75f231ea461b.png)