Add authenticator.Assertion interfaces
Add github.com/RangelReale/osin as a dependency for plugin/pkg/oauth
Add github.com/RangelReale/osincli as a dependency for plugin/pkg/oauth
Add github.com/gorilla/sessions, github.com/gorilla/securecookie, github.com/gorilla/context as a dependencies for plugin/pkg/auth
Add OAuth plugin API and registry, client and grant interfaces
Add OAuth plugin token authenticator
Add osin-based OAuth server impl
Add session support, and a session-based authenticator.Request
Add CSRF support (session-based, cookie-based, allow-all, and test)
Add grant and login flows
Register oauth types into api, wire oauth server