pgsql: Allow BASE_BACKUP to be throttled

Allow BASE_BACKUP to be throttled

A new MAX_RATE option allows imposing a limit to the network transfer
rate from the server side.  This is useful to limit the stress that
taking a base backup has on the server.

pg_basebackup is now able to specify a value to the server, too.

Author: Antonin Houska

Patch reviewed by Stefan Radomski, Andres Freund, Zoltán Böszörményi,
Fujii Masao, and Álvaro Herrera.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/ef5856fd9b77ef9d0d0c31fb314bb61bbfb1d704

Modified Files
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doc/src/sgml/protocol.sgml             |   18 ++++-
doc/src/sgml/ref/pg_basebackup.sgml    |   21 +++++
src/backend/replication/basebackup.c   |  137 +++++++++++++++++++++++++++++++-
src/backend/replication/repl_gram.y    |    8 +-
src/backend/replication/repl_scanner.l |    1 +
src/bin/pg_basebackup/pg_basebackup.c  |  134 +++++++++++++++++++++++++++----
src/include/replication/basebackup.h   |    7 ++
7 files changed, 306 insertions(+), 20 deletions(-)