[ADDITION] Google Authentication for Logins

 * Adds Google Authentication for Logins
   * Uses https://github.com/PHPGangsta/GoogleAuthenticator as the Library
   * Twofactor & GAuth are enabled by default on this build, as it's now a user setting

 * Includes generic user settings that can be used elsewhere

* Adds Account Settings page for users
  * Adds the ability for users to control their own twofactor settings
  * Adds the ability for users to lock twofactor settings (email confirmation)