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 basic auth password authenticate
Add session support
Add CSRF support
Add grant and login flows
Test registering API REST resources