Feature: Render a server side page for social network metatag

[gabrieledarrigo]

When a user try to share a page directly on Facebok or Google Plus the content can't be crawled by their bot; so, even if the meta tag are dynamically generated the y can't be useto display the right content.
Implements a method on the server that look at the user agent of the crawlers and redirect them to a server generated page, withe meta tag correctly generated.
The page can be empty.
See here for some example:

http://www.michaelbromley.co.uk/blog/171/enable-rich-social-sharing-in-your-angularjs-app

https://github.com/michaelbromley/angular-social-demo

$1 Variables:

http://stackoverflow.com/questions/13369285/what-does-the-1-argument-in-this-rewritecond-do

Consider even another approach with PhantomJS (due to the difficulty of the routing after the redirect)

[gabrieledarrigo]

Completed.
Instead of servin an html file the application render an index.ejs file with the metatag correctly populated