Add support for hybridauth

Hybridauth is a nice little module that leverages the library of the same name.

Currently the Hybridauth module attempts to open an authentication window from the modal login, but the url is being encoded somewhere and for Google at least the authentication page is not loading correctly.

The issue is a little larger than this, and I will probably be digging deeper in the next week.

Corresponding case in hybridauth: https://drupal.org/node/2033755