pgsql: Fix erroneous implementation of -s in postmaster.c (the switch

Log Message:
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Fix erroneous implementation of -s in postmaster.c (the switch doesn't take
an optarg). Add some comments noting that code in three different files has
to be kept in sync. Fix erroneous description of -S switch (it sets work_mem
not silent_mode), and do some light copy-editing elsewhere in postgres-ref.

Tags:
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REL8_2_STABLE

Modified Files:
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pgsql/doc/src/sgml/ref:
postgres-ref.sgml (r1.47 -> r1.47.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/postgres-ref.sgml.diff?r1=1.47&r2=1.47.2.1)
pgsql/src/backend/main:
main.c (r1.105 -> r1.105.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/main/main.c.diff?r1=1.105&r2=1.105.2.1)
pgsql/src/backend/postmaster:
postmaster.c (r1.505 -> r1.505.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/postmaster/postmaster.c.diff?r1=1.505&r2=1.505.2.1)
pgsql/src/backend/tcop:
postgres.c (r1.518 -> r1.518.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/postgres.c.diff?r1=1.518&r2=1.518.2.1)