pgsql: Change default of recovery_target_timeline to 'latest'

Change default of recovery_target_timeline to 'latest'

This is what one usually wants for recovery and almost always wants
for a standby.

Discussion: https://www.postgresql.org/message-id/flat/6dd2c23a-4162-8469-410f-bfe146e28c0c@2ndquadrant.com/
Reviewed-by: David Steele <david@pgmasters.net>
Reviewed-by: Michael Paquier <michael@paquier.xyz>

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/0acb3bc33af11a57d560cbce5a74246eb3e642db

Modified Files
--------------
doc/src/sgml/config.sgml                      |  8 ++++++--
doc/src/sgml/high-availability.sgml           |  6 +++---
src/backend/access/transam/xlog.c             |  2 +-
src/backend/utils/misc/guc.c                  |  7 ++++---
src/backend/utils/misc/postgresql.conf.sample |  2 +-
src/bin/pg_rewind/RewindTest.pm               |  2 --
src/test/recovery/t/004_timeline_switch.pl    |  1 -
src/test/recovery/t/009_twophase.pl           | 12 ------------
src/test/recovery/t/012_subtransactions.pl    | 12 ------------
9 files changed, 15 insertions(+), 37 deletions(-)