Simplify query_planner's API by having it return the top-level RelOptInfo.

Formerly, query_planner returned one or possibly two Paths for the topmost
join relation, so that grouping_planner didn't see the join RelOptInfo
(at least not directly; it didn't have any hesitation about examining
cheapest_path->parent, though).  However, correct selection of the Paths
involved a significant amount of coupling between query_planner and
grouping_planner, a problem which has gotten worse over time.  It seems
best to give up on this API choice and instead return the topmost
RelOptInfo explicitly.  Then grouping_planner can pull out the Paths it
wants from the rel's path list.  In this way we can remove all knowledge
of grouping behaviors from query_planner.

The only real benefit of the old way is that in the case of an empty
FROM clause, we never made any RelOptInfos at all, just a Path.  Now
we have to gin up a dummy RelOptInfo to represent the empty FROM clause.
That's not a very big deal though.

While at it, simplify query_planner's API a bit more by having the caller
set up root->tuple_fraction and root->limit_tuples, rather than passing
those values as separate parameters.  Since query_planner no longer does
anything with either value, requiring it to fill the PlannerInfo fields
seemed pretty arbitrary.

This patch just rearranges code; it doesn't (intentionally) change any
behaviors.  Followup patches will do more interesting things.
pgtest:  allow passing parameters, e.g. -s/--silent
Previously only -n was recognized.
Fix assertion failure by an immediate shutdown.

In PM_WAIT_DEAD_END state, checkpointer process must be dead already.
But an immediate shutdown could make postmaster's state machine
transition to PM_WAIT_DEAD_END state even if checkpointer process is
still running,  and which caused assertion failure. This bug was introduced
in commit 457d6cf049c57cabe9b46ea13f26138040a214ec.

This patch ensures that postmaster's state machine doesn't transition to
PM_WAIT_DEAD_END state in an immediate shutdown while checkpointer
process is running.
Message style improvements
Message punctuation and pluralization fixes
Document how auto_explain.log_timing can be changed.
Docs:  Document to_*() Julian values are integers
Backpatch to 9.3.
Per request from Marc Dahn
docs:  mention Julian is midnight _UTC_
(Yes, there was no UTC back then, but we compute it that way.)
Backpatch to 9.3.
PL/Python: Adjust the regression tests for Python 3.3

Similar to 2cfb1c6f77734db81b6e74bcae630f93b94f69be, the order in which
dictionary elements are printed is not reliable.  This reappeared in the
tests of the string representation of result objects.  Reduce the test
case to one result set column so that there is no question of order.
pg_dump:  avoid schema qualification for ALTER ... OWNER

We already use search_path to specify the schema, so there is no need
for pg_dump to schema-qualify the name.  Also remove dead code.
9.3 release notes:  move foreign table item

Move item about foreign data wrappers supporting inserts/updates/deletes
to object manipulation.

From Etsuro Fujita
Emit a log message if output is about to be redirected away from stderr.

We've seen multiple cases of people looking at the postmaster's original
stderr output to try to diagnose problems, not realizing/remembering that
their logging configuration is set up to send log messages somewhere else.
This seems particularly likely to happen in prepackaged distributions,
since many packagers patch the code to change the factory-standard logging
configuration to something more in line with their platform conventions.

In hopes of reducing confusion, emit a LOG message about this at the point
in startup where we are about to switch log output away from the original
stderr, providing a pointer to where to look instead.  This message will
appear as the last thing in the original stderr output.  (We might later
also try to emit such link messages when logging parameters are changed
on-the-fly; but that case seems to be both noticeably harder to do nicely,
and much less frequently a problem in practice.)

Per discussion, back-patch to 9.3 but not further.
Update Emacs configuration

Update emacs.samples with new configuration snippets that match pgindent
et al. formatting more accurately and follow Emacs Lisp best practices
better.

Add .dir-locals.el with a subset of that configuration for casual
editing and viewing.

Reviewed-by: Dimitri Fontaine <dimitri@2ndQuadrant.fr>
Reviewed-by: Noah Misch <noah@leadboat.com>
Remove Assert that matview is not in system schema from REFRESH.

We don't want to prevent an extension which creates a matview from
being installed in pg_catalog.

Issue was raised by Hitoshi Harada.
Backpatched to 9.3.
docs:  document TRIM "comma" syntax

This syntax is supported by the parser, but is non-standard.

_Not_ backpatched to 9.3 in case we change our minds.
Remove ph_may_need from PlaceHolderInfo, with attendant simplifications.

The planner logic that attempted to make a preliminary estimate of the
ph_needed levels for PlaceHolderVars seems to be completely broken by
lateral references.  Fortunately, the potential join order optimization
that this code supported seems to be of relatively little value in
practice; so let's just get rid of it rather than trying to fix it.

Getting rid of this allows fairly substantial simplifications in
placeholder.c, too, so planning in such cases should be a bit faster.

Issue noted while pursuing bugs reported by Jeremy Evans and Antonin
Houska, though this doesn't in itself fix either of their reported cases.
What this does do is prevent an Assert crash in the kind of query
illustrated by the added regression test.  (I'm not sure that the plan for
that query is stable enough across platforms to be usable as a regression
test output ... but we'll soon find out from the buildfarm.)

Back-patch to 9.3.  The problem case can't arise without LATERAL, so
no need to touch older branches.
Improve error message when view is not updatable

Avoid using the term "updatable" in confusing ways.  Suggest a trigger
first, before a rule.
Treat timeline IDs as unsigned in replication parser

Timeline IDs are unsigned ints everywhere, except the replication parser
treated them as signed ints.
Add tab completion for \dx in psql
Don't allow ALTER MATERIALIZED VIEW ADD UNIQUE.

Was accidentally allowed, but not documented and lacked support
for rename or drop once created.

Per report from Noah Misch.