Fix typos
Keep track of transaction commit timestamps

Transactions can now set their commit timestamp directly as they commit,
or an external transaction commit timestamp can be fed from an outside
system using the new function TransactionTreeSetCommitTsData().  This
data is crash-safe, and truncated at Xid freeze point, same as pg_clog.

This module is disabled by default because it causes a performance hit,
but can be enabled in postgresql.conf requiring only a server restart.

A new test in src/test/modules is included.

Catalog version bumped due to the new subdirectory within PGDATA and a
couple of new SQL functions.

Authors: Álvaro Herrera and Petr Jelínek

Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert
Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven
Singer, Peter Eisentraut
doc: Fix markup

In the spirit of d34b48a021b181e30c53280d336820740f67570b

Per buildfarm member guaibasaurus, via Stefan Kaltenbrunner.
Move PG_AUTOCONF_FILENAME definition

Since this is not something that a user should change,
pg_config_manual.h was an inappropriate place for it.

In initdb.c, remove the use of the macro, because utils/guc.h can't be
included by non-backend code.  But we hardcode all the other
configuration file names there, so this isn't a disaster.
Fix SHLIB_PREREQS use in contrib, allowing PGXS builds

dblink and postgres_fdw use SHLIB_PREREQS = submake-libpq to build libpq
first.  This doesn't work in a PGXS build, because there is no libpq to
build.  So just omit setting SHLIB_PREREQS in this case.

Note that PGXS users can still use SHLIB_PREREQS (although it is not
documented).  The problem here is only that contrib modules can be built
in-tree or using PGXS, and the prerequisite is only applicable in the
former case.

Commit 6697aa2bc25c83b88d6165340348a31328c35de6 previously attempted to
address this by creating a somewhat fake submake-libpq target in
Makefile.global.  That was not the right fix, and it was also done in a
nonportable way, so revert that.
Remove USE_VPATH make variable from PGXS

The user can just set VPATH directly.  There is no need to invent
another variable.
Revert haphazard pgxs makefile changes

These changes were originally submitted as "adds support for VPATH with
USE_PGXS", but they are not necessary for VPATH support, so they just
add more lines of code for no reason.
Fix PGXS vpath build when PostgreSQL is built with vpath

PGXS computes srcdir from VPATH, PostgreSQL proper computes VPATH from
srcdir, and doing both results in an error from make.  Conditionalize so
only one of these takes effect.
Document that pg_stat_*_tables.n_tup_upd includes n_tup_hot_upd.

Author: Peter Geoghegan
Don't dump core if pq_comm_reset() is called before pq_init().

This can happen if an error occurs in a standalone backend.  This bug
was introduced by commit 2bd9e412f92bc6a68f3e8bcb18e04955cc35001d.

Reported by Álvaro Herrera.
Fix pg_xlogdump's calculation of full-page image data.

The old formula was completely bogus with the new WAL record format.
Print wal_log_hints in the rm_desc routing of a parameter-change record.

It was an oversight in the original commit.

Also note in the sample config file that changing wal_log_hints requires a
restart.

Michael Paquier. Backpatch to 9.4, where wal_log_hints was added.
Print new track_commit_timestamp in rm_desc of a parameter-change record.

Michael Paquier
Remove erroneous EXTRA_CLEAN line from Makefile.

After commit da34731, these files are not generated files anymore.

Adam Brightwell
Don't include file type bits in tar archive's mode field.

The "file mode" bits in the tar file header is not supposed to include the
file type bits, e.g. S_IFREG or S_IFDIR. The file type is stored in a
separate field. This isn't a problem in practice, all tar programs ignore
the extra bits, but let's be tidy.

This came up in a discussion around bug #11949, reported by Hendrik Grewe,
although this doesn't fix the issue with tar --append. That turned out to be
a bug in GNU tar. Schilly's tartest program revealed this defect in the tar
created by pg_basebackup.

This problem goes as far as we we've had pg_basebackup, but since this
hasn't caused any problems in practice, let's be conservative and fix in
master only.
Give a proper error message if initdb password file is empty.

Used to say just "could not read password from file "...": Success", which
isn't very informative.

Mats Erik Andersson. Backpatch to all supported versions.
Tweaks for recovery_target_action

Rename parameter action_at_recovery_target to
recovery_target_action suggested by Christoph Berg.

Place into recovery.conf suggested by Fujii Masao,
replacing (deprecating) earlier parameters, per
Michael Paquier.
Event Trigger for table_rewrite

Generate a table_rewrite event when ALTER TABLE
attempts to rewrite a table. Provide helper
functions to identify table and reason.

Intended use case is to help assess or to react
to schema changes that might hold exclusive locks
for long periods.

Dimitri Fontaine, triggering an edit by Simon Riggs

Reviewed in detail by Michael Paquier
Remove duplicate code in heap_prune_chain()

No need to set tuple tableOid twice

Jim Nasby
Correct recovery_target_action docs

From Michael Paquier