Force entire swap process to be portrait.
Although this is usually regarded as poor form, it is currently better
than the alternative which is the whole swap process poohing itself
when a device is rotated. In the future, it may be worthwhile investing
in designing a proper UX for landscape swap too. However the process
of swapping can be quite complex if not presented well, and so it might
end up being too much work to maintain two different UXes for landscape
and portrait.
See merge request !89
c39e1cab6e