Added Google API lib
Switched to Google Oauth2 for login.

Copy init.php.in to init.php

Set database username, password

Set $GoogleClientID and $GoogleClientSecret

To get those:

* Navigate to the Google Cloud Console. https://cloud.google.com/console
* Click on the Create Project button on top of the page, enter the following values and then click on the Create button.
* Once the project has been created, open the APIs & auth group (left navigation pannel) and then click on Consent screen and set it up (this is just for what is shown to the user, values not important)
* Open the APIs & auth group in the left pannel (if it's not already open) and click on Credentials.
* Click on the CREATE NEW CLIENT ID button, enter/tick the following values and then click on the Create Client ID button.

  Application type: Web Application
  Authorized Javascript origins: http://crash.replex.org
  Authorized redirect URI: http://crash.replex.org/process_login.php
  (replace with appropriate links. imporant bit is url to process_login.php)

You will now have Client ID and Client secret