merge sonic master to update#4

Merged

yangbashuang merged 25 commits intoCentecNetworks:masterfrom

sonic-net:master

May 4, 2018

Commits on Apr 25, 2018

Commits on Apr 27, 2018

[docker-lldpd]: Various fixes (#1650)

pavel-shirshov
authored and
lguohan
committed
[sonic-utilities]: Submodule update for sonic-utilities (#1653)

prsunny
authored and
lguohan
committed

Commits on Apr 28, 2018

[mellanox]: Update SAI version to 1.11.4 and SDK to 4.2.7303 (#1655)

andriymoroz-mlnx
authored and
lguohan
committed

Commits on May 1, 2018

Commits on May 2, 2018

Commits on May 4, 2018