Add the new/updated content marker to all the views where it makes sense

Includes these Views:

- open_atrium_news
- open_atrium_content

On the Views that are Panes, the new field is totally optional. The user can disable it in the Pane settings if they don't want it.

Here are some screenshots:

![selection_041](https://f.cloud.github.com/assets/191561/2472228/cdc5019e-b032-11e3-93c5-385bdd91714f.png)

![selection_042](https://f.cloud.github.com/assets/191561/2472229/d24eb188-b032-11e3-931b-d4de9daace23.png)