[RFC] simplify headers

[Benjamin Kosnik]

> I like the idea, but... that's a big change to make in stage three
> development.  Clearly the rules don't apply quite as tightly to the library,
> but maybe this should wait until after we branch for 3.1?

Hmm. 

To me, this is a reason to do this now. Note, there were more substantial 
changes being made to the headers much further into the 3.0 cycle: it's this 
that I'm trying to avoid.

I'm hoping other people can try this out and give me some feedback. 
Especially on BSD, hpux, and Solaris.

Since the patch is pretty unwieldly, here's a tarball, on the ftp server:
libstdc++-v3.0.96-pre1.tar.bz2

We can start a seperate thread on the release process, and near 
and future development plans, which might be a good idea.

> Note that the @file doxygen hooks will need to be updated.  (I can do this
> after the patch goes in.)

I was hoping you'd say this!

-benjamin