Dan Williams authored Sep 24, 2014 and Thomas Haller committed Dec 04, 2015

Unrealized devices aren't backed by kernel resources and so won't know
all of their attributes.  That means three things:

1) they must update their attributes when they become realized
2) they must clear those attributes when unrealized
3) they must be looser in checking compatible connections until
they are realized

This requires that the setup() function be split into two parts, start & finish,
because finish must be run after add_device()

Also, we can simplify whether to pay attention to 'recheck-assume', which
is now dependent on priv->is_nm_owned, because the only case where NM should
*not* listen for the 'recheck-assume' signal is when the device is a
software device created by NM itself.  That logic was previously spread
across the callers of add_device() but is now consolidated into
nm-manager.c::device_realized() and nm-device.c::nm_device_create_and_realize().