dont use cif as a series identifier

This is a result of putting blogs into the series container here: https://github.com/guardian/frontend/pull/7279 and treplicates the logic we use to populate the left -hand meta data where cif is a special case. Essentially what this boils down to is - don't use cif as a series identifier in and of its self but the first non cif blog or series tag,

So

Before: 
![series-before](https://cloud.githubusercontent.com/assets/986155/5266760/b7fb4072-7a43-11e4-8f45-63c2d978f126.png)

After: 
![series-after](https://cloud.githubusercontent.com/assets/986155/5266775/ca817798-7a43-11e4-96b2-499c57d1767a.png)