@mzikherman: Render a google+ authorship tag when possible

There's some discussion on the seo@ list about establishing our pages' "authorship" to build "authority." I don't know what those mean but thought our blog should do the same. The instructions are for the author to add the site to the "contributor to" section of their Google+ profile, and for the site to include a link back to the author's Google+ profile. (No one wants to link to their Google+ profiles, so we include a `<link>` tag instead.)

https://support.google.com/webmasters/answer/2539557?hl=en

Search results then look like:
![](http://f.cl.ly/items/1i3F2K1t0q2c2q0o1C2a/Screen%20Shot%202014-06-19%20at%205.11.47%20PM.png)