pgsql: Implement ALTER TABLE .. SET LOGGED / UNLOGGED

Implement ALTER TABLE .. SET LOGGED / UNLOGGED

This enables changing permanent (logged) tables to unlogged and
vice-versa.

(Docs for ALTER TABLE / SET TABLESPACE got shuffled in an order that
hopefully makes more sense than the original.)

Author: Fabrízio de Royes Mello
Reviewed by: Christoph Berg, Andres Freund, Thom Brown
Some tweaking by Álvaro Herrera

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/f41872d0c1239d36ab03393c39ec0b70e9ee2a3c

Modified Files
--------------
doc/src/sgml/ref/alter_table.sgml         |   64 ++++----
src/backend/commands/cluster.c            |   46 +++---
src/backend/commands/matview.c            |    9 +-
src/backend/commands/tablecmds.c          |  239 ++++++++++++++++++++++++++++-
src/backend/parser/gram.y                 |   17 +-
src/bin/psql/tab-complete.c               |    4 +-
src/include/commands/cluster.h            |    2 +-
src/include/nodes/parsenodes.h            |    2 +
src/include/parser/kwlist.h               |    1 +
src/test/regress/expected/alter_table.out |   91 +++++++++++
src/test/regress/sql/alter_table.sql      |   52 +++++++
11 files changed, 472 insertions(+), 55 deletions(-)