Some people seem to feel uncomfortable with autotools-multilib, because
it depends on autotools-utils.

Instead of arguing whether it makes sense or not I'd propose a similar
autotools related eclass.

I also attach an example conversion of media-libs/libexif (the
maintainer wants to keep the changes minimal).
Effectively I am only (almost) changing the function names and not the
ebuild code.

Feel free to propose a different eclass name.