Sync log_handler module from Oslo

Ibf28ba17f Remove the notifier and its dependencies from log.py

Move the code related to the publish error handler out of the
log module so its easier for other projects to consume it

Closes-bug: #1240349
(cherry picked from commit 1a961bf7e64e7a1610b6be0a5d68bda242352ec4)

Conflicts:
	openstack-common.conf

Change-Id: Ib97bc01b60d7ea6c2e6bc3f0229deffbadbf18cc
Merge "Sync log_handler module from Oslo" into stable/havana