Log Message:
-----------
Mention that transactions can complete in a different numeric order, for
PITR recovery.
Modified Files:
--------------
pgsql-server/doc/src/sgml:
backup.sgml (r2.42 -> r2.43)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/backup.sgml.diff?r1=2.42&r2=2.43)