For now, ignore everything that is not the primary, and do not use the
converted total.
This is based on http://i.imgur.com/TNcLbPB.jpg
as I have 0 in all currencies for now.
Limitations for now:
* Only French-style (UUU,CC and not UUU.CC) balances; the choice is not left up to the user so
it's hard to test
* No history (should be easy to add)
