fix the an Unexpected API Error issue in flavor API

The flavors.add_flavor_access and flavors.remove_flavor_access
require admin privilege in DB level but the policy doesn't
require it and the exception isn't catched in the api. So the
bug arise. The privilege check in DB level is not necessary,
but it need more tests and can be remove in other patch or
blue-print.

This use extension_authorizer instead of soft_extension_authorizer
in the action of flavor_access, in order to raise exception.

Closes-Bug: #1217679
DocImpact

Change-Id: I0b1231f47fffaf99f330de02956bfe8d7cd4b920
Merge "fix the an Unexpected API Error issue in flavor API"
xenapi: refactor: move UpdateGlanceImage to common

During the review of https://review.openstack.org/41651 it was
recommended to move UpdateGlanceImage to a common library. A bug was
filed to deal with the refactors. This change fixes the first part.

Fixes bug 1220596

Change-Id: I95ae89525b7e6768c5a70364945d5a10cb906d88
XenAPI: Fix translation of metadetails in aggregates

https://review.openstack.org/#/c/43157/ added a translation from the sqlalchemy model to
the instance object replacing metadetails with metadata.

This added more traces in general for XenAPI (when we queried whether we were using
aggregates) and actually broke the host aggregate functionality

Change-Id: I87195753931945b6e1ecf75bc81575a6fa03068e
Closes-bug: 1232179
xenapi: post install scriptlet to rpm

A post install script that creates the /images directory on xenserver,
and sets up the trust relationship.

Change-Id: Id57e3a3ab2782550468c6aa4c01059ceb7cc81ab