Removal of pre-ISO C++ items from include/backwards

[Joe Buck]

On Thu, Oct 25, 2007 at 08:17:58PM -0700, Mark Mitchell wrote:
> The maintenance burden argument always used to remove stuff.  I've used
> it myself plenty of times.  Sometimes, it really is too painful.  But,
> sometimes -- and, again, I consider myself guilty -- we've ripped things
> out under the banner of tidiness and maintenance that imposed a lot of
> pain on users.

In this case, it is proposed to move hash_set and hash_map from <ext/..>
to <backward/..>.  How does that decrease the maintainance burden?  It just
breaks code.