pgsql: Reference doc "examples" section for pg_dump options that often

Reference doc "examples" section for pg_dump options that often need
complex quoting, e.g. -t and -n.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/26174d5fd0dec01bbbc4e766ed32b9a50a019c29

Modified Files
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doc/src/sgml/ref/pg_dump.sgml | 8 +++++---
1 files changed, 5 insertions(+), 3 deletions(-)