Support for retrieving user based on client#256

jankapunkt merged 2 commits intonode-oauth:release-5.0.0node-oauth/node-oauth2-server:release-5.0.0from

jorenvandeweyer:feature/pass-client-to-get-userjorenvandeweyer/node-oauth2-server:feature/pass-client-to-get-userCopy head branch name to clipboard