reporting currencies & integrity

[linas@linas.org]

It's been rumoured that Christian Stimming said:
> Recall that the "reporting currency" can be changed anytime (= I agree 
> with Bill on this). 

As do I.

> I disagree with Linas in that accounts should have a 
> "reporting currency". 

I wasn't trying to say that they should.  I was instead stating that
that they do, in the current implementation.   That's how the engine
works today.   I want to change this,  and I think I'm finally
getting the idea of how. 

--linas