aupg - aupg_src: I am so ashamed to commit this patch.

Log Message:
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I am so ashamed to commit this patch. I created a BS function for PG < 8.3 to
prevent the (already hackish) txid code from failing to parse on a not-found function.

The longer-term solution is probably to eval the code based on version using
plpgsql and 'execute.'

Modified Files:
--------------
aupg_src/sql:
audit_infrastructure.sql (r1.18 -> r1.19)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/aupg/aupg_src/sql/audit_infrastructure.sql.diff?r1=1.18&amp;r2=1.19)