Sync service module from oslo-incubator

This is needed for the stop method now implemented in service.py used here:
https://review.openstack.org/#/c/72564

Current oslo-incubator commit on HEAD
ad3c887fbfc81ac3502a3e49c1ed6c2824029c25

Change-Id: I66901c0c42472be1aadab803958932bcb9be8ee1
Added note to neutron.conf

Added note to neutron.conf which clarifies where database
connection attribute should be set.

Change-Id: Ic0631cff789046528cae8622d935b65ae9b012cb
Closes-Bug: #1261298
Merge "Added note to neutron.conf"
Merge "Sync service module from oslo-incubator"