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This has been discussed in bug 541009.

This has been discussed in bug 541009.

This has been discussed in bug 541009.

This has been discussed in bug 541009.

This has been discussed in bug 541009.

Mainly removing unused h/v includes, but also adding some that
will be necessary as replacements.

We need pay attention the the request mode when doing size allocation.
The code was using request mode for requisition, but orientation
for allocation.

Also add a reftest that exhibits the issue, courtesy of
Benjamin Otte.

Use align and margin widget properties instead.