[Proj] Indefinite delays with project library

[Charles Wilson]

The biggest mistake most newly autotooled projects make is to allow the
config.h to become publicly visible via the project's public header
files.  (And some long-established projects do it to).

Normally, public header files shouldn't care about "gee does this system
have a working vfork()".  However, *types* matter -- and it's a bit of
an art to make sure that the types used in your public header file don't
depend on macros defined in config.h (like HAVE_UINT64_T, etc).

I don't know if I count as a "guru" but I'll try to take a look sometime
in the next week.

--
Chuck