feed pagination with isotope (bug 1053405)

The paginated elements fade in! How awesome.

- Rather than hacking builder, I handled the pagination manually to get it into the Isotope flow.

![screen shot 2014-08-14 at 1 18 44 pm](https://cloud.githubusercontent.com/assets/674727/3926300/40402ccc-23f0-11e4-8663-6a52a9bc6e8f.png)
![screen shot 2014-08-14 at 1 18 50 pm](https://cloud.githubusercontent.com/assets/674727/3926304/441c1b94-23f0-11e4-8426-99998996fd50.png)
![screen shot 2014-08-14 at 1 18 53 pm](https://cloud.githubusercontent.com/assets/674727/3926305/44fd104a-23f0-11e4-804c-f371b46a4463.png)