pgsql: pg_dump can now dump large objects even in plain-text output

Log Message:
-----------
pg_dump can now dump large objects even in plain-text output mode, by
using the recently added lo_create() function. The restore logic in
pg_restore is greatly simplified as well, since there's no need anymore
to try to adjust database references to match a new set of blob OIDs.

Modified Files:
--------------
pgsql/doc/src/sgml:
backup.sgml (r2.67 -> r2.68)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/backup.sgml.diff?r1=2.67&r2=2.68)
installation.sgml (r1.236 -> r1.237)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/installation.sgml.diff?r1=1.236&r2=1.237)
pgsql/doc/src/sgml/ref:
pg_dump.sgml (r1.77 -> r1.78)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_dump.sgml.diff?r1=1.77&r2=1.78)
pg_dumpall.sgml (r1.50 -> r1.51)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_dumpall.sgml.diff?r1=1.50&r2=1.51)
pg_restore.sgml (r1.52 -> r1.53)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_restore.sgml.diff?r1=1.52&r2=1.53)
pgsql/src/bin/pg_dump:
README (r1.5 -> r1.6)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/README.diff?r1=1.5&r2=1.6)
pg_backup.h (r1.35 -> r1.36)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup.h.diff?r1=1.35&r2=1.36)
pg_backup_archiver.c (r1.110 -> r1.111)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup_archiver.c.diff?r1=1.110&r2=1.111)
pg_backup_archiver.h (r1.64 -> r1.65)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup_archiver.h.diff?r1=1.64&r2=1.65)
pg_backup_custom.c (r1.30 -> r1.31)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup_custom.c.diff?r1=1.30&r2=1.31)
pg_backup_db.c (r1.61 -> r1.62)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup_db.c.diff?r1=1.61&r2=1.62)
pg_backup_db.h (r1.10 -> r1.11)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup_db.h.diff?r1=1.10&r2=1.11)
pg_backup_files.c (r1.25 -> r1.26)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup_files.c.diff?r1=1.25&r2=1.26)
pg_backup_null.c (r1.14 -> r1.15)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup_null.c.diff?r1=1.14&r2=1.15)
pg_dump.c (r1.409 -> r1.410)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c.diff?r1=1.409&r2=1.410)