[ldapfeed] use LDAP_SCOPES to find user-scope We already have LDAP_SCOPES dict defining possible scopes, this avoid possible code injection from config... Thus we can drop global variables already defined in LDAP_SCOPES since they are not used directly anymore.

change_attribute_type('CWUser', 'last_login_time', 'TZDatetime')
change_attribute_type('CWSource', 'latest_retrieval', 'TZDatetime')
drop_attribute('CWSource', 'synchronizing')
add_attribute('CWSource', 'in_synchronization')