pgsql: Add recovery_target='immediate' option.

Add recovery_target='immediate' option.

This allows ending recovery as a consistent state has been reached. Without
this, there was no easy way to e.g restore an online backup, without
replaying any extra WAL after the backup ended.

MauMau and me.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/71c6a8e375b138af8aa46d80226ea9e98f2b94bc

Modified Files
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doc/src/sgml/backup.sgml                        |    2 +-
doc/src/sgml/recovery-config.sgml               |   44 ++++++++++++++++------
src/backend/access/transam/recovery.conf.sample |    6 +++
src/backend/access/transam/xlog.c               |   46 ++++++++++++++++++++++-
src/include/access/xlog.h                       |    3 +-
5 files changed, 86 insertions(+), 15 deletions(-)