Changes User() to _User and User=_User, to overwrite the User class in an own...

Changes User() to _User and User=_User, to overwrite the User class in an own blueprint Added LDAP_USER_ATTRIBUTE_MAPPING to be able to make the ldap attribute names configurable Added LDAP_USER_FILTER to configure the filter instead of the default (objectClass=person) Added LDAP_GROUP_FILTER to configure the filter instead of the default (objectClass=groupOfUniqueNames)