pg_dump: Reduce use of global variables

Most pg_dump.c global variables, which were passed down individually to
dumping routines, are now grouped as members of the new DumpOptions
struct, which is used as a local variable and passed down into routines
that need it.  This helps future development efforts; in particular it
is said to enable a mode in which a parallel pg_dump run can output
multiple streams, and have them restored in parallel.

Also take the opportunity to clean up the pg_dump header files somewhat,
to avoid circularity.

Author: Joachim Wieland, revised by Álvaro Herrera
Reviewed by Peter Eisentraut
Blind attempt at fixing Win32 pg_dump issues

Per buildfarm failures
Print planning time only in EXPLAIN ANALYZE, not plain EXPLAIN.

We've gotten enough push-back on that change to make it clear that it
wasn't an especially good idea to do it like that.  Revert plain EXPLAIN
to its previous behavior, but keep the extra output in EXPLAIN ANALYZE.
Per discussion.

Internally, I set this up as a separate flag ExplainState.summary that
controls printing of planning time and execution time.  For now it's
just copied from the ANALYZE option, but we could consider exposing it
to users.
Support timezone abbreviations that sometimes change.

Up to now, PG has assumed that any given timezone abbreviation (such as
"EDT") represents a constant GMT offset in the usage of any particular
region; we had a way to configure what that offset was, but not for it
to be changeable over time.  But, as with most things horological, this
view of the world is too simplistic: there are numerous regions that have
at one time or another switched to a different GMT offset but kept using
the same timezone abbreviation.  Almost the entire Russian Federation did
that a few years ago, and later this month they're going to do it again.
And there are similar examples all over the world.

To cope with this, invent the notion of a "dynamic timezone abbreviation",
which is one that is referenced to a particular underlying timezone
(as defined in the IANA timezone database) and means whatever it currently
means in that zone.  For zones that use or have used daylight-savings time,
the standard and DST abbreviations continue to have the property that you
can specify standard or DST time and get that time offset whether or not
DST was theoretically in effect at the time.  However, the abbreviations
mean what they meant at the time in question (or most recently before that
time) rather than being absolutely fixed.

The standard abbreviation-list files have been changed to use this behavior
for abbreviations that have actually varied in meaning since 1970.  The
old simple-numeric definitions are kept for abbreviations that have not
changed, since they are a bit faster to resolve.

While this is clearly a new feature, it seems necessary to back-patch it
into all active branches, because otherwise use of Russian zone
abbreviations is going to become even more problematic than it already was.
This change supersedes the changes in commit 513d06ded et al to modify the
fixed meanings of the Russian abbreviations; since we've not shipped that
yet, this will avoid an undesirably incompatible (not to mention incorrect)
change in behavior for timestamps between 2011 and 2014.

This patch makes some cosmetic changes in ecpglib to keep its usage of
datetime lookup tables as similar as possible to the backend code, but
doesn't do anything about the increasingly obsolete set of timezone
abbreviation definitions that are hard-wired into ecpglib.  Whatever we
do about that will likely not be appropriate material for back-patching.
Also, a potential free() of a garbage pointer after an out-of-memory
failure in ecpglib has been fixed.

This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that
caused it to produce unexpected results near a timezone transition, if
both the "before" and "after" states are marked as standard time.  We'd
only ever thought about or tested transitions between standard and DST
time, but that's not what's happening when a zone simply redefines their
base GMT offset.

In passing, update the SGML documentation to refer to the Olson/zoneinfo/
zic timezone database as the "IANA" database, since it's now being
maintained under the auspices of IANA.
Fix pg_dump for UPDATE policies

pg_dump had the wrong character for update and so was failing when
attempts were made to pg_dump databases with UPDATE policies.

Pointed out by Fujii Masao (thanks!)
Re-pgindent src/bin/pg_dump/*.

Seems to have gotten rather messy lately, as a consequence of a couple
of large recent commits.
Fix core dump in pg_dump --binary-upgrade on zero-column composite type.

This reverts nearly all of commit 28f6cab61ab8958b1a7dfb019724687d92722538
in favor of just using the typrelid we already have in pg_dump's TypeInfo
struct for the composite type.  As coded, it'd crash if the composite type
had no attributes, since then the query would return no rows.

Back-patch to all supported versions.  It seems to not really be a problem
in 9.0 because that version rejects the syntax "create type t as ()", but
we might as well keep the logic similar in all affected branches.

Report and fix by Rushabh Lathia.
Fix bug in handling of connections that pg_receivexlog creates.

Previously pg_receivexlog created new connection for WAL streaming
even though another connection which had been established to create
or delete the replication slot was being left. This caused the unused
connection to be left uselessly until pg_receivexlog exited.
This bug was introduced by the commit d9f38c7.

This patch changes pg_receivexlog so that the connection for
the replication slot is reused for WAL streaming.

Andres Freund, slightly modified by me, reviewed by Michael Paquier
Avoid core dump in _outPathInfo() for Path without a parent RelOptInfo.

Nearly all Paths have parents, but a ResultPath representing an empty FROM
clause does not.  Avoid a core dump in such cases.  I believe this is only
a hazard for debugging usage, not for production, else we'd have heard
about it before.  Nonetheless, back-patch to 9.1 where the troublesome code
was introduced.  Noted while poking at bug #11703.
Declare mkdtemp() only if we're providing it.

Follow our usual style of providing an "extern" for a standard library
function only when we're also providing the implementation.  This avoids
issues when the system headers declare the function slightly differently
than we do, as noted by Caleb Welton.

We might have to go to the extent of probing to see if the system headers
declare the function, but let's not do that until it's demonstrated to be
necessary.

Oversight in commit 9e6b1bf258170e62dac555fc82ff0536dfe01d29.  Back-patch
to all supported branches, as that was.
doc: Clean up pg_recvlogical reference page

This needed a general cleanup of wording, typos, outdated terminology,
formatting, and hard-to-understand and borderline incorrect information.

Also tweak the pg_receivexlog page a bit to make the two more
consistent.
doc:  restrictions on alter database moving default tablespace

Mention tablespace must be empty and no one connected to the database.

Report by Josh Berkus
interval:  tighten precision specification

interval precision can only be specified after the "interval" keyword if
no units are specified.

Previously we incorrectly checked the units to see if the precision was
legal, causing confusion.

Report by Alvaro Herrera
Shorten warning about hash creation

Also document that PITR is also affected.
Allow setting effective_io_concurrency even on unsupported systems

This matches the behavior of other parameters that are unsupported on
some systems (e.g., ssl).

Also document the default value.
psql: Improve \pset without arguments

Revert the output of the individual backslash commands that change print
settings back to the 9.3 way (not showing the command name in
parentheses).  Implement \pset without arguments separately, showing all
settings with values in a table form.
initdb: Fix compiler error in USE_PREFETCH case
Fix typos.

Etsuro Fujita
Fix typos.

David Rowley
Fix file-identification comment in contrib/pgcrypto/pgcrypto--1.2.sql.

Cosmetic oversight in commit 32984d8fc3dbb90a3fafb69fece0134f1ea790f9.

Marko Tiikkaja