[patch] stephen's staging headers patch

[Benjamin Kosnik]

> Yeah, I think I fixed that fairly soon after I posted the original patch.
> A small but important change.

Hmm. What's the change?

> The problem with soft links is (as far as my experience goes), they don't
> support dependency tracking by timestamp.  If files are soft linked and I
> change one, the timestamp of the link itself does not change, make
> fails to notice the change, and things don't get rebuilt.  Of course, I haven't
> tried this in practice, so I don't know if it's really a problem or not.

Hmm. Well, perhaps we can try this patch both ways, with and without 
links. 

-benjamin