Add More button to Community pages

Resolves #970 by adding a More button to the bottom of Community pages, which loads the current page limit + next dozen. Nothing fancy. Also, the amount of whitespace that appears due to not having enough participants to fill the page bugs me a bit. There will be a querystring in the URL with this button too. But other than that…

![screen shot 2014-03-13 at 4 42 33 pm](https://f.cloud.github.com/assets/65468/2414962/0786079a-aaf0-11e3-9500-f10a3002935b.png)