pgsql: Add pg_rewind --no-sync

Add pg_rewind --no-sync

This is an option consistent with what pg_dump and pg_basebackup provide
which is useful for leveraging the I/O effort when testing things, not
to be used in a production environment.

Author: Michael Paquier
Reviewed-by: Heikki Linnakangas
Discussion: /messages/by-id/20180325122607.GB3707@paquier.xyz

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/8a00b96aa994b5c2c1a03c70e7a4719c919e8798

Modified Files
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doc/src/sgml/ref/pg_rewind.sgml | 16 ++++++++++++++++
src/bin/pg_rewind/RewindTest.pm | 6 ++++--
src/bin/pg_rewind/pg_rewind.c | 12 ++++++++++--
3 files changed, 30 insertions(+), 4 deletions(-)