Do not add current tenant to private flavor access

Avoid adding the current tenant to the flavor access list when
a private flavor is created. In ordeir to add tenants to the
flavor access list we should use the add_tenant api.

Tempest has to be updated accordingly:
https://review.openstack.org/81551

Documentation has to be updated as well:
https://review.openstack.org/82175

Partially (just for the V2 API rather than V2 and V3)
reverts commit 6ba248635b70860a44e486e7739efa4cc6612ce6

Fixes unittest which was added in the original commit so it checks
for the behaviour we have now rather than the behaviour after the
backwards incompatible change which is being reverted.

Change-Id: I731081b6df0d96df1bc1763d214d28c62bbbb51c
Closes-Bug: #1286297
Change libvirt close callback to use green thread

The native thread that calls the close callback is being
used to update a host's status, potentially causing threading
issues, since it involves operations that should only be
performed by green threads. This change fixes the issue
by limiting the native thread's interaction to adding data
to a queue and leaving the remaining work for
a green thread.

Closes-Bug: #1290487
Closes-Bug: #1293641

Change-Id: I59c14da15e4655dc4bf21d4de3d509472b146f7a
Fix availability-zone option miss when creates an instance

In test_availability_zone.py the availability-zone option is
used as 'availability_zone' which should be modified to
'os-availability-zone:availability_zone'.

Change-Id: I765d07b699ecb425dadccb22af834b11f52ff5b0
Closes-Bug: #1270811
Merge "Do not add current tenant to private flavor access"
Merge "Change libvirt close callback to use green thread"
Merge "Fix availability-zone option miss when creates an instance"