pgsql: Replace raw timezone source data with IANA's new compactformat.

Replace raw timezone source data with IANA's new compact format.

Traditionally IANA has distributed their timezone data in pure source
form, replete with extensive historical comments.  As of release 2017c,
they've added a compact single-file format that omits comments and
abbreviates command keywords.  This form is way shorter than the pure
source, even before considering its allegedly better compressibility.
Hence, let's distribute the data in that form rather than pure source.

I'm pushing this now, rather than at the next timezone database update,
so that it's easy to confirm that this data file produces compiled zic
output that's identical to what we were getting before.

Discussion: https://postgr.es/m/1915.1511210334@sss.pgh.pa.us

Branch
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REL9_4_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/10aa064c953e5e7e7cccf545558a8336e5fdb220

Modified Files
--------------
src/timezone/Makefile          |    6 +-
src/timezone/README            |   19 +-
src/timezone/data/africa       | 1225 ------------
src/timezone/data/antarctica   |  340 ----
src/timezone/data/asia         | 3142 ------------------------------
src/timezone/data/australasia  | 1793 -----------------
src/timezone/data/backward     |  128 --
src/timezone/data/backzone     |  675 -------
src/timezone/data/etcetera     |   78 -
src/timezone/data/europe       | 3845 -------------------------------------
src/timezone/data/factory      |   10 -
src/timezone/data/northamerica | 3419 ---------------------------------
src/timezone/data/pacificnew   |   27 -
src/timezone/data/southamerica | 1793 -----------------
src/timezone/data/systemv      |   37 -
src/timezone/data/tzdata.zi    | 4146 ++++++++++++++++++++++++++++++++++++++++
16 files changed, 4160 insertions(+), 16523 deletions(-)