====== <#google_oauth2callback> ======
This function check the google OAuth 2.0 authentification (https://developers.google.com/accounts/docs/OAuth2WebServer),
if success login the user or register him. Typically, the website open a popup to the url
https://accounts.google.com/o/oauth2/auth with a redirect_uri to a link that contain this function. The function
itself will be responsible to login or create (and login) the user and the template
of this function will be responsible to close the popup and reload the parent document
==== Parameters ====
^ Name ^ Mandatory ^ Default ^ Description ^
| template | No | | Used to build the content of the result |
| client_id | Yes | | The client_id obtained during application registration (https://code.google.com/apis/console/) |
| client_secret | Yes | | The client secret obtained during application registration (https://code.google.com/apis/console/) |
| redirect_uri | No | /authentication/google_oauth2callback/ | The URI registered with the application |
==== Example ====
<#{google_oauth2callback client_id="..." client_secret="..." redirect_uri="...">
<#{template>
<#}template>
<#}google_oauth2callback>