pgsql: Replace "transaction log" with "write-ahead log"

Replace "transaction log" with "write-ahead log"

This makes documentation and error messages match the renaming of "xlog"
to "wal" in APIs and file naming.

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/c1a7f64b4a720a662ecec809bc9e289f35e887ad

Modified Files
--------------
doc/src/sgml/backup.sgml | 2 +-
doc/src/sgml/config.sgml | 2 +-
doc/src/sgml/func.sgml | 64 +++++++++++++++++-----------------
doc/src/sgml/high-availability.sgml | 6 ++--
doc/src/sgml/monitoring.sgml | 26 +++++++-------
doc/src/sgml/protocol.sgml | 2 +-
doc/src/sgml/recovery-config.sgml | 2 +-
doc/src/sgml/ref/checkpoint.sgml | 4 +--
doc/src/sgml/ref/initdb.sgml | 2 +-
doc/src/sgml/ref/pg_basebackup.sgml | 32 ++++++++---------
doc/src/sgml/ref/pg_receivewal.sgml | 16 ++++-----
doc/src/sgml/ref/pgbench.sgml | 2 +-
doc/src/sgml/ref/pgtestfsync.sgml | 2 +-
doc/src/sgml/release-10.sgml | 2 +-
src/backend/access/transam/timeline.c | 2 +-
src/backend/access/transam/transam.c | 2 +-
src/backend/access/transam/xlog.c | 31 ++++++++--------
src/backend/access/transam/xlogfuncs.c | 2 +-
src/backend/access/transam/xlogutils.c | 2 +-
src/backend/postmaster/checkpointer.c | 5 ++-
src/backend/postmaster/pgarch.c | 5 ++-
src/backend/postmaster/postmaster.c | 2 +-
src/bin/initdb/initdb.c | 18 +++++-----
src/bin/pg_basebackup/pg_basebackup.c | 36 +++++++++----------
src/bin/pg_basebackup/pg_receivewal.c | 8 ++---
src/bin/pg_basebackup/receivelog.c | 14 ++++----
src/bin/pg_basebackup/streamutil.c | 2 +-
src/bin/pg_resetwal/pg_resetwal.c | 8 ++---
src/bin/pg_rewind/timeline.c | 2 +-
src/bin/pg_waldump/pg_waldump.c | 2 +-
src/include/access/xlog.h | 2 +-
src/include/access/xlog_internal.h | 2 +-
src/include/access/xlogdefs.h | 2 +-
src/test/perl/PostgresNode.pm | 6 ++--
34 files changed, 157 insertions(+), 160 deletions(-)