[?Future] Adding robots functionality to front end :)

(When implemented) this would require a new `searchable` (TINYINT) column in the `article` db table.
![sqlchange](https://f.cloud.github.com/assets/2001446/1785350/d01da1c2-68e2-11e3-8912-d57fe5d36bf9.png)

These changes take place on article and user pages. 
entrepreneurj/FelixOnline@a0778aab547087146334fecf9b81f6a56a4bc5a3 This adds the noindex robots meta tag if the article is hidden (searchable==0)
entrepreneurj/FelixOnline@d21143678061bcdcafad0f2f08d211cbcdd2f1d3 This adds the noindex robots meta tag to a user page if any of the user's articles are hidden with a0778aab547087146334fecf9b81f6a56a4bc5a3