DFP: Fix bug where all ads where refreshing...

...regardless of the `data-refresh` attribute

Also moved the resizing stuff into `dfp.js`, rather than letting `common` do it

![1254999468_monocycle-shit-faceplant](https://cloud.githubusercontent.com/assets/74132/2926991/4e828ac4-d764-11e3-905f-c4dcbc78a1a7.gif)