pgsql: Don't uselessly rewrite, truncate, VACUUM, or ANALYZE partitione

Don't uselessly rewrite, truncate, VACUUM, or ANALYZE partitioned tables.

Also, recursively perform VACUUM and ANALYZE on partitions when the
command is applied to a partitioned table. In passing, some related
documentation updates.

Amit Langote, reviewed by Michael Paquier, Ashutosh Bapat, and by me.

Discussion: http://postgr.es/m/47288cf1-f72c-dfc2-5ff0-4af962ae5c1b@lab.ntt.co.jp

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/3c3bb99330aa9b4c2f6258bfa0265d806bf365c3

Modified Files
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doc/src/sgml/ddl.sgml | 47 ++++++++++++++++++------------------
doc/src/sgml/ref/analyze.sgml | 7 ++++--
doc/src/sgml/ref/vacuum.sgml | 4 +++-
src/backend/commands/analyze.c | 37 +++++++++++++++++++----------
src/backend/commands/tablecmds.c | 15 +++++++++---
src/backend/commands/vacuum.c | 51 +++++++++++++++++++++++++++++++++++++---
6 files changed, 116 insertions(+), 45 deletions(-)