performance-improvement-by-reducing-wal-for-update-operation (patch 2 of 1)

'git apply --summary --stat --apply --verbose' output was:

 src/backend/access/common/heaptuple.c |   47 +++
 src/backend/access/heap/heapam.c      |   95 +++++-
 src/backend/access/transam/xlog.c     |   22 +
 src/backend/utils/adt/pg_lzcompress.c |  500 ++++++++++++++++++++++++++++++++-
 src/backend/utils/misc/guc.c          |   12 +
 src/include/access/heapam_xlog.h      |   15 +
 src/include/access/htup_details.h     |    5
 src/include/access/xlog.h             |    1
 src/include/utils/pg_lzcompress.h     |    6
 src/test/regress/expected/update.out  |   70 +++++
 src/test/regress/sql/update.sql       |   67 ++++
 11 files changed, 803 insertions(+), 37 deletions(-)

For original context, see http://www.postgresql.org/message-id/009601ce76f5$746479d0$5d2d6d70$@kommi@huawei.com
Adding travis.yml