Fix display of images in Rebuild Instance

The image list in Rebuild Instance is constructed from (id, name)
pairs. As the name is a string, the transform function is never called
unless image name is None. In that case it crashes the view.

This change:
  - Builds the image list with (id, image) so the correct thing
      is passed to the transform
  - Corrects the size/name attributes
  - Handles None display name (displays id instead)
  - Set the name of one of the public images in glance_data.py to
      None so errors like these are picked up in the future.

Change-Id: I0d1f8594cccc404c0dd6f254b70d23789817dd06
Closes-bug: #1258349
(cherry picked from commit c720b4f90e59ad76ef846c8ba5b6b6d91883ee66)
Merge branch 'stable/havana' of https://github.com/openstack/horizon into stable/havana_routerrules