pgsql: vacuumdb: Add option --analyze-in-stages

vacuumdb: Add option --analyze-in-stages

Add vacuumdb option --analyze-in-stages which runs ANALYZE three times
with different configuration settings, adopting the logic from the
analyze_new_cluster.sh script that pg_upgrade generates. That way,
users of pg_dump/pg_restore can also use that functionality.

Change pg_upgrade to create the script so that it calls vacuumdb instead
of implementing the logic itself.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/c92c3d50d7fbe7391b5fc864b444346b2db29ffe

Modified Files
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contrib/pg_upgrade/check.c | 58 ++-----------------------
doc/src/sgml/ref/vacuumdb.sgml | 20 +++++++++
src/bin/scripts/t/102_vacuumdb_stages.pl | 16 +++++++
src/bin/scripts/vacuumdb.c | 70 +++++++++++++++++++++++-------
4 files changed, 94 insertions(+), 70 deletions(-)