pgsql: pg_basebackup: Allow client-side LZ4 (de)compression.

pg_basebackup: Allow client-side LZ4 (de)compression.

LZ4 compression can now be performed on the client using
pg_basebackup -Ft --compress client-lz4, and LZ4 decompression of
a backup compressed on the server can be performed on the client
using pg_basebackup -Fp --compress server-lz4.

Dipesh Pandit, reviewed and tested by Jeevan Ladhe and Tushar Ahuja,
with a few corrections - and some documentation - by me.

Discussion: http://postgr.es/m/CAN1g5_FeDmiA9D8wdG2W6Lkq5CpubxOAqTmd2et9hsinTJtsMQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/751b8d23b788580bbff7463e3959f9a92a95b28a

Modified Files
--------------
doc/src/sgml/ref/pg_basebackup.sgml | 27 +-
src/bin/pg_basebackup/Makefile | 1 +
src/bin/pg_basebackup/bbstreamer.h | 3 +
src/bin/pg_basebackup/bbstreamer_lz4.c | 431 ++++++++++++++++++++++++++
src/bin/pg_basebackup/pg_basebackup.c | 44 ++-
src/bin/pg_verifybackup/t/009_extract.pl | 7 +-
src/bin/pg_verifybackup/t/010_client_untar.pl | 111 +++++++
src/tools/msvc/Mkvcbuild.pm | 1 +
8 files changed, 606 insertions(+), 19 deletions(-)