pgsql: Don't require bleeding-edge timezone data in timestamptz regress

Don't require bleeding-edge timezone data in timestamptz regression test.

The regression test cases added in commits b2cbced9e et al depended in part
on the Russian timezone offset changes of Oct 2014. While this is of no
particular concern for a default Postgres build, it was possible for a
build using --with-system-tzdata to fail the tests if the system tzdata
database wasn't au courant. Bjorn Munch and Christoph Berg both complained
about this while packaging 9.4rc1, so we probably shouldn't insist on the
system tzdata being up-to-date. Instead, make an equivalent test using a
zone change that occurred in Venezuela in 2007. With this patch, the
regression tests should pass using any tzdata set from 2012 or later.
(I can't muster much sympathy for somebody using --with-system-tzdata
on a machine whose system tzdata is more than three years out-of-date.)

Branch
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REL9_0_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/e1f91066fd4d718161eb9cb9bacaa706273a4ba1

Modified Files
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src/test/regress/expected/timestamptz.out | 216 +++++++++++++++--------------
src/test/regress/sql/timestamptz.sql | 115 +++++++--------
2 files changed, 168 insertions(+), 163 deletions(-)