Add extra log output and message id to logline

THe message id is useful when multiple updates come in, makes it unique.
Add lock to rfc2136 handling to fix deadlock issue

We receive
Mar 03 07:40:06 UPDATE (9044) from 127.0.0.3 for test.dyndns: Caught SSqlException: Failed to execute mysql_query, perhaps connection died? Err=1: Deadlock found when trying to get lock; try restarting transaction; Sending ServFail!

if we don't.
Remove old/unused code - Guard is never used
fix auth and ordername after replacing a record

The replaceRRSet does not keep the auth & ordername fields.