Log Message:
-----------
Clarify documentation that journaling is not required for WAL or data files.
Modified Files:
--------------
pgsql/doc/src/sgml:
wal.sgml (r1.55 -> r1.56)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/wal.sgml?r1=1.55&r2=1.56)