pgsql: Simplify handling of the timezone GUC by making initdb choose th

Simplify handling of the timezone GUC by making initdb choose the default.

We were doing some amazingly complicated things in order to avoid running
the very expensive identify_system_timezone() procedure during GUC
initialization. But there is an obvious fix for that, which is to do it
once during initdb and have initdb install the system-specific default into
postgresql.conf, as it already does for most other GUC variables that need
system-environment-dependent defaults. This means that the timezone (and
log_timezone) settings no longer have any magic behavior in the server.
Per discussion.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/ca4af308c32d03db5fbacb54d6e583ceb904f268

Modified Files
--------------
doc/src/sgml/config.sgml | 14 +-
doc/src/sgml/datatype.sgml | 21 +-
doc/src/sgml/ref/set.sgml | 4 +-
src/backend/bootstrap/bootstrap.c | 4 -
src/backend/commands/variable.c | 43 +-
src/backend/postmaster/postmaster.c | 15 -
src/backend/tcop/postgres.c | 4 -
src/backend/utils/error/elog.c | 29 +-
src/backend/utils/misc/guc-file.l | 1 -
src/backend/utils/misc/guc.c | 21 +-
src/backend/utils/misc/postgresql.conf.sample | 4 +-
src/bin/initdb/.gitignore | 1 +
src/bin/initdb/Makefile | 11 +-
src/bin/initdb/findtimezone.c | 1224 ++++++++++++++++++++++++
src/bin/initdb/initdb.c | 25 +-
src/include/pgtime.h | 23 +-
src/include/utils/guc.h | 2 -
src/timezone/localtime.c | 28 +
src/timezone/pgtz.c | 1265 +------------------------
19 files changed, 1372 insertions(+), 1367 deletions(-)