Passport and LevelDB pre-release

• Oauth Server functionality:
  • implements the authorization code authorization flow see example here
  • implements the client credential authorization flow see example here
  • implements the implicit grant see example here
• Storage:
  • Proper handling of Oauth2 clients (through entities of type client)
  • Storage of tokens
  • Generic storage of entities
• Policies:
  • enforcement of source and target policies to ensure proper read and write enforcement on attributes.