Windows: wintypes import issue

[Lucian Petrut]

In some environments, the Cinder Volume fails to start with the following error:

AttributeError: 'module' object has no attribute 'wintypes'

In order to avoid this, wintypes must be explicitly imported in vhdutils instead
of relying on the ctypes import and accessing wintypes as an attribute.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/165874

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/165874
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=c14cec2634a34f19a91a1587d4c148e8c22ef14d
Submitter: Jenkins
Branch: master

commit c14cec2634a34f19a91a1587d4c148e8c22ef14d
Author: Lucian Petrut <email address hidden>
Date: Sun Mar 15 23:32:48 2015 +0200

    Windows: Fixes wintypes import issue in vhdutils

    At the moment, wintypes is accessed as a ctypes attribute. In
    some environments, this raises an AttributeError. For this
    reason, the Windows iSCSI and Windows SMBFS drivers fail to
    initialize.

    In order to avoid this, wintypes must be explicitly imported in
    vhdutils.

    Change-Id: I78bb916b0da3f7540e7a428d0bab10edc6a5b963
    Closes-Bug: #1434130