It was recently added to open-iscsi the functionality to disable
automatic LUN scans on iscsid start, on login, and on reception of
AEN/AER messages reporting LUN data has changed.
Those 3 cases were one of the causes why Nova-CPU and Cinder-Volumes
nodes would have unexpected devices. With this new feature we can
prevent them from appearing unnexpectedly.
This patch adds the mechanism required to configure our sessions for
manual scans in a backward compatible way.
Manual scans are enabled setting `node.session.scan` to `manual`.
Change-Id: I146a74f9f79c68a89677b9b26a324e06a35886f2
f67d46c538