Backport changes for openstack-doc-tools

Copy over changes from master for gating with openstack-doc-tools.

This backports also Change-Id: Iff5409daaa8b6e62ab59902e7c47914540a0321c:
    Do not use ndash in filenames

    Ndashes in filenames will cause problems with some filesystems
    and also showed a bug in pbr when running tox.

    Note that none of these files was actually used.
    There is already a copy without the ndashes in common/figures.

Change-Id: Ic6db63f873d8c9346d38ccceb07afffbc99db32d