Show series or blog in meta

In the left hand meta, for blogs and series, show which ever blog or series tag is first in the list: 

Before: 
![series-or-blog-before](https://cloud.githubusercontent.com/assets/986155/5169713/af2e2664-7401-11e4-9cac-64710fd28186.png)

After:
![blog-or-series-after](https://cloud.githubusercontent.com/assets/986155/5169718/bc2aa48c-7401-11e4-93e8-db3668c4505f.png)