Update version of Jetty-server lib used in components-common-oauth

Currently, Oauth component uses 8.1.17.v20150415 version of Jetty server.
It conflicts with Rest service, which depends on spring depending on javax-servlet:3.1
(while jetty depends on javax-servlet:3.0)

So, we need to change version to 9.3.11.v20160721 and update implementation according new jetty API

Technical implementation

I ended up upgrading to jetty 9.3.14.v20161028 (to match spring boot dependencies)