Support preprod cells (again)

Change-Id: I82ed9c41f835eebbfa5e7a999ac3eb87a1a45da8
Hack to disable the region selector

Change-Id: I8f81bd8398f8fae69e6aef8b9216294ed39806c1
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 parameters
    - Handles None display name (displays id instead)

Change-Id: I0d1f8594cccc404c0dd6f254b70d23789817dd06
Show volume quota graphs if totalVolumesUsed >= 0

commit 9bca5d3680ee21d2b92ba6766f13b5d216fc477f fixed the
volume quota display, but quotas are hidden if a project has a used
quota of 0. I don't think we should hide the quotas in this case,
as users still need to know how much quota is available, even if they
haven't used any of it yet.

Change-Id: I72c0fae1a51cafabfcde8970c94097069083dd06
Partial-Bug: #1244875
(cherry picked from commit 9f1da374af2e6780e8b9e767052285e1d20b04fe)