Copy-editing for recent window-functions documentation rewrite.

Fix grammar, put back some removed information, rearrange for clarity.
Another round of planner fixes for LATERAL.

Formerly, subquery pullup had no need to examine other entries in the range
table, since they could not contain any references to the subquery being
pulled up.  That's no longer true with LATERAL, so now we need to be able
to visit rangetable subexpressions to replace Vars referencing the
pulled-up subquery.  Also, this means that extract_lateral_references must
be unsurprised at encountering lateral PlaceHolderVars, since such might be
created when pulling up a subquery that's underneath an outer join with
respect to the lateral reference.
Make use of LATERAL in information_schema.sequences view.

It said "XXX: The following could be improved if we had LATERAL" ...
so let's do that.

No catversion bump since either version of the view works fine.
Allow OLD and NEW in multi-row VALUES within rules.

Now that we have LATERAL, it's fairly painless to allow this case, which
was left as a TODO in the original multi-row VALUES implementation.
Remove obsolete comment.
Fix typo in comment.
Don't get confused if a WAL partial record header has xl_tot_len == 0.

If a WAL record header was split across pages, but xl_tot_len was 0, we
would get confused and conclude that we had already read the whole record,
and proceed to CRC check it. That can lead to a crash in RecordIsValid(),
which isn't careful to not read beyond end-of-record, as defined by
xl_tot_len.

Add an explicit sanity check for xl_tot_len <= SizeOfXlogRecord. Also,
make RecordIsValid() more robust by checking in each step that it doesn't
try to access memory beyond end of record, even if a length field in the
record's or a backup block's header is bogus.

Per report and analysis by Tom Lane.
Fix bugs in contrib/pg_trgm's LIKE pattern analysis code.

Extraction of trigrams did not process LIKE escape sequences properly,
leading to possible misidentification of trigrams near escapes, resulting
in incorrect index search results.

Fujii Masao
Tab complete "TABLE whatever DROP CONSTRAINT" with a constraint name.

Jeff Janes
Improved tab completion for CLUSTER VERBOSE.

Jeff Janes
Remove external PID file on postmaster exit
Teach compiler that ereport(>=ERROR) does not return

When elevel >= ERROR, we add an abort() call to the ereport() macro to
give the compiler a hint that the ereport() expansion will not return,
but the abort() isn't actually reached because the longjmp happens in
errfinish().

Because the effect of ereport() varies with the elevel, we cannot use
standard compiler attributes such as noreturn for this.
Add a note to the MVCC chapter that some things aren't transactional.

Craig Ringer, slightly edited by me.
Improve C comments in GetSnapshotData.

Move discussion of why our algorithm for taking snapshots in recovery
to a more appropriate location in the function, and delete incorrect
mention of taking a lock.
Fix dumping of security_barrier views with circular dependencies.

If a view has circular dependencies, pg_dump splits it into a CREATE TABLE
and a CREATE RULE command to break the dependency loop.  However, if the
view has reloptions, those options cannot be applied in the CREATE TABLE
command, because views and tables have different allowed reloptions so
CREATE TABLE would reject them.  Instead apply the reloptions after the
CREATE RULE, using ALTER VIEW SET.
Avoid somewhat-theoretical overflow risks in RecordIsValid().

This improves on commit 51fed14d73ed3acd2282b531fb1396877e44e86a by
eliminating the assumption that we can form <some pointer value> +
<some offset> without overflow.  The entire point of those tests is that
we don't trust the offset value, so coding them in a way that could wrap
around if the buffer happens to be near the top of memory doesn't seem
sound.  Instead, track the remaining space as a size_t variable and
compare offsets against that.

Also, improve comment about why we need the extra early check on
xl_tot_len.
Update 9.2 release notes to reflect commits to date.

I was unable to entirely resist the temptation to copy-edit related
entries, but will save most of that for a separate pass.
Mark DateTimeParseError() noreturn

This avoids a warning from clang 3.2 about an uninitialized variable
'dtype' in date_in().
Fix install-strip on Mac OS X

There was a hack put into install-sh to call strip with the correct
options on Mac OS X.  But that never worked, because configure
disabled stripping on that platform altogether.  So remove that dead
code, and while we're at it, update install-sh to the latest upstream
source (from Automake).

Instead, set up the right strip options in programs.m4, so this now
actually works the way it was originally intended.
Document that pg_reload_conf() is also an easy way to reload the
configuration file.