Serialization dependencies muck up configure-on-demand

[Nathanael Nerode]

Daniel said:
>Well, I'm not sure how useful of a goal that is; I suppose it would
>speed up re-making when most directories don't need to be updated or
>updated substantially.  I don't see a better way without being truly

Specifically, when nothing needs to be reconfigured, but lots of things 
do need to be rebuilt, this is very useful. :-)  This is quite a common 
situation.

--Nathanael