Ticket 47622 - Automember betxnpreoperation - transaction not aborted when group entry does not exist
Bug Description: If the group defined in the automember plugin does not exist, than any add operation
that should trigger an update, succeeds even though the automember update failed.
Fix Description: Return an error if a automember post operation update fails - previously we always
returned success.
Updated plugin_call_func() to check the result of betxn postop plugins.
Also added return text to the result message when a betxn plugin fails. This is
useful for clients to explain why the operation failed.
https://fedorahosted.org/389/ticket/47622
Jenkins: passed
Valgrind: passed
Coverity: passed
Reviewed by: rmeggins(Thanks!)