Add sponsorship to Series container

Actually a bit more complicated than I'd hoped, because the series component is ajax-ed in, after the adverts (might) have been displayed, so we need to make another call to dfp for the sponsorship logo

e.g.

![screen shot 2014-09-25 at 15 15 54](https://cloud.githubusercontent.com/assets/74132/4406079/6193404e-44c0-11e4-9b2c-4b076be8a028.png)

I am a big fan of aligning =. You are using it in the file above but not here. It will be nice to have consistency (ideally across the whole codebase). Should we maybe create guideline for this?