pgsql: Honor PGCTLTIMEOUT environment variable for pg_regress' startup

Honor PGCTLTIMEOUT environment variable for pg_regress' startup wait.

In commit 2ffa86962077c588 we made pg_ctl recognize an environment variable
PGCTLTIMEOUT to set the default timeout for starting and stopping the
postmaster. However, pg_regress uses pg_ctl only for the "stop" end of
that; it has bespoke code for starting the postmaster, and that code has
historically had a hard-wired 60-second timeout. Further buildfarm
experience says it'd be a good idea if that timeout were also controlled
by PGCTLTIMEOUT, so let's make it so. Like the previous patch, back-patch
to all active branches.

Discussion: <13969(dot)1461191936(at)sss(dot)pgh(dot)pa(dot)us>

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/1b22368ff7a8eb7cdee987c417c26bf524995e33

Modified Files
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src/test/regress/pg_regress.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)