Log Message:
-----------
Add some documentation about how we WAL-log filesystem actions.
Per a question from Robert Haas.
Modified Files:
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pgsql/src/backend/access/transam:
README (r1.13 -> r1.14)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/README?r1=1.13&r2=1.14)