https://developers.google.com/identity/protocols/OAuth2UserAgent#overview https://stormpath.com/blog
https://developers.google.com/identity/protocols/OAuth2UserAgent#overview
https://stormpath.com/blog/secure-single-page-app-problem
https://stormpath.com/blog/token-auth-spa
https://stormpath.com/blog/nodejs-jwt-create-verify
