Suppress dead, unportable src/port/crypt.c code.

This file used __int64, which is specific to native Windows, rather than
int64.  Suppress the long-unused union field of this type.  Noticed on
Cygwin x86_64 with -lcrypt not installed.  Back-patch to 9.0 (all
supported versions).
pg_ctl: Cast DWORD values to avoid -Wformat warnings.

This affects pg_ctl alone, because pg_ctl takes the exceptional step of
calling Windows API functions in a Cygwin build.
Fix quoting in the add_to_path Makefile macro.

The previous quoting caused "make -C src/bin check" to ignore, rather
than add to, any LD_LIBRARY_PATH content from the environment.
Back-patch to 9.4, where the macro was introduced.
Increase number of hash join buckets for underestimate.

If we expect batching at the very beginning, we size nbuckets for
"full work_mem" (see how many tuples we can get into work_mem,
while not breaking NTUP_PER_BUCKET threshold).

If we expect to be fine without batching, we start with the 'right'
nbuckets and track the optimal nbuckets as we go (without actually
resizing the hash table). Once we hit work_mem (considering the
optimal nbuckets value), we keep the value.

At the end of the first batch, we check whether (nbuckets !=
nbuckets_optimal) and resize the hash table if needed. Also, we
keep this value for all batches (it's OK because it assumes full
work_mem, and it makes the batchno evaluation trivial). So the
resize happens only once.

There could be cases where it would improve performance to allow
the NTUP_PER_BUCKET threshold to be exceeded to keep everything in
one batch rather than spilling to a second batch, but attempts to
generate such a case have so far been unsuccessful; that issue may
be addressed with a follow-on patch after further investigation.

Tomas Vondra with minor format and comment cleanup by me
Reviewed by Robert Haas, Heikki Linnakangas, and Kevin Grittner
Add --latency-limit option to pgbench.

This allows transactions that take longer than specified limit to be counted
separately. With --rate, transactions that are already late by the time we
get to execute them are skipped altogether. Using --latency-limit with
--rate allows you to "catch up" more quickly, if there's a hickup in the
server causing a lot of transactions to stall momentarily.

Fabien COELHO, reviewed by Rukh Meski and heavily refactored by me.
doc: improve USING and NATURAL JOIN descriptions

Patch by David G Johnston
Consistently use NULL for invalid GUC unit strings

Patch by Euler Taveira
docs: error for adding  _validated_ domains for existing uses

Report by David G Johnston