pgsql: Add --encoding to pg_dump.

Log Message:
-----------
Add --encoding to pg_dump.

The Problem: Occassionally a DBA needs to dump a database to a new
encoding. In instances where the current encoding, (or lack of an
encoding, like SQL_ASCII) is poorly supported on the target database
server, it can be useful to dump into a particular encoding. But,
currently the only way to set the encoding of a pg_dump file is to
change client_encoding in postgresql.conf and restart postmaster.
This is more than a little awkward for production systems.

Magnus Hagander

Modified Files:
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pgsql/doc/src/sgml/ref:
pg_dump.sgml (r1.78 -> r1.79)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_dump.sgml.diff?r1=1.78&r2=1.79)
pgsql/src/bin/pg_dump:
pg_dump.c (r1.414 -> r1.415)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c.diff?r1=1.414&r2=1.415)