Authentication with Google accounts

When a user clicks the log in button, genomics-status will first ask permission to access the user's account basic information:
![screen shot 2014-02-05 at 14 51 05](https://f.cloud.github.com/assets/1574147/2087575/219b1146-8e6e-11e3-9669-175f96fe5fcf.png)
When the user accepts, genomics-status will connect to the google API with the received token and collect information from the user, concretely we're interested on the email, that we will check on our database. If the user is authorized (his/her mail is on the database), he/she will get access to genomics-status:
![screen shot 2014-02-05 at 14 50 48](https://f.cloud.github.com/assets/1574147/2087585/5638c8b2-8e6e-11e3-84d9-a71890142948.png)
Otherwise he/she will see this:
![screen shot 2014-02-05 at 14 51 20](https://f.cloud.github.com/assets/1574147/2087590/6b9570ac-8e6e-11e3-9045-88437c1ad941.png)
Clicking my name will open the default mail client with a new message to me with subject "Genomics Status access request - \<mail of the user\>"

Thanks for your help @alneberg !