Seo breadcrumbs


![breadcrumb](https://cloud.githubusercontent.com/assets/986155/2999741/f1cb255a-dd19-11e3-98f0-acfd8911cf8f.png)

Adds a breadcrumb component for seo purposes: This has the form: Primary Nav -> Secondary Nav(if present) -> Primary tag. The Breadcrumb markup is also removed from the header.

![breadcrumb](https://cloud.githubusercontent.com/assets/986155/2999818/0f93456c-dd1b-11e3-8779-4cef2070e7f0.png)

Before and After from http://www.google.com/webmasters/tools/richsnippets

Before: 
![google-web-after](https://cloud.githubusercontent.com/assets/986155/2999830/3aeceb1e-dd1b-11e3-958b-6cdca3f23fdb.png)

After:
![google-breadcrumbs-after](https://cloud.githubusercontent.com/assets/986155/2999832/464e0916-dd1b-11e3-86f2-b9d629fbd7a2.png)