I must raise a small voice in protest, here..  I don't think we should
   be selectively building one part of the tree over another one.  My opinion



the problem here is that the US folks (or, at least jason?) want a crypto
tree that they can change _entirely_.  to me, that means that crypto-us
has to be *entirely* self contained.  frank and i discussed this on ICB the
other day (we agreed to disagree).  he feels that we'll have version skew
as any files that *are* the same in both will only have changes feeding one
direction.  i agree that this is an issue, though i doubt it has any 
relevance in *reality* as i don't foresee such changes happening often or
without similar changes elsewhere.


i'd prefer crypto-us didn't exist *at all* but given that it does and that
isn't likely to change for a while, it should be a first-class citizen.