pgsql: Finish disabling reduced-lock-levels-for-DDL feature.

Finish disabling reduced-lock-levels-for-DDL feature.

Previous patch only covered the ALTER TABLE changes, not changes in other
commands; and it neglected to revert the documentation changes.

Branch
------
master

Details
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http://git.postgresql.org/pg/commitdiff/a195e3c34f1eeb6a607c342121edf48e49067ea9

Modified Files
--------------
doc/src/sgml/mvcc.sgml | 9 ++++-----
src/backend/commands/tablecmds.c | 17 +++++++++++------
src/backend/commands/trigger.c | 18 ++++--------------
src/backend/rewrite/rewriteDefine.c | 12 +++++-------
4 files changed, 24 insertions(+), 32 deletions(-)