based on example provided by Mario Camou at http://www.tecnoguru.com/blog/2014/07/07/implementing-http-basic-authentication-with-spray/
LDAP realm implementation that retrieves group information from LDAP and matches the 'member' attribute values of each group against the given user.
Apache Shiro based authenticator for the Spark JobServer, the authenticator realm must be specified in the ini file for Shiro
minimal user info, for more advanced permission checking, it might be necessary to add more properties such as group memberships
LDAP realm implementation that retrieves group information from LDAP and matches the 'member' attribute values of each group against the given user.
not all LDAP installations use the member property.... we might have to add memberOf matches as well and others