Add link to create Auth0 Account #28
 Validate settings before saving #24
 Support redirecting to arbitrary URLs after login is succesful #29
 Add link to create Auth0 Account #28 (always visible)
Now it saves both in cookies and session, issue #29
 Support redirecting to arbitrary URLs after login is succesful #29 (now it uses state without cookies nor session)
Merge pull request #30 from auth0/dev

Issues #24, #28 & #29