documented anonymous access
Merge pull request #191 from FriendsOfSymfony/feature/anonymous-access-documentation

documented anonymous access
Corrected depending on the developers' branch
Added method implements the removal of the used auth code
removed minimum-stability
added tests of OAuthStorage::markAuthCodeAsUsed()

#193
sync with latest FriendsOfSymfony/oauth2-php
Ensure user is logged out when client is authorized by pre-authorization event
Merge branch 'master' into develop
Merge branch 'ensure-logout-authorized' into develop