#55 Berlin upgrade display

[Chris Shaffer]

* When placing tile #581 (green upgrade) in Berlin and trying it both ways
it will go, the tokens that are already there (#9 and KPEV, which I formed
from #7) are shown, respectively, along the SE and NW edges, rather than the
NE and SW which are the existing connections they must keep. They move to
the correct places once I make the tile lay final, but showing them wrong
makes it harder to place the tile correctly.

Reported by John David Galt