Fix bug when reentrant requests are used to return regular files
Fix bug when reentrant requests are used to return regular files

Response headers were not correctly set, in particular the Content-Length
header. This bug was fixed by refactoring the way reentrant requests are
handled.

jgrinstead/yaws,jgrinstead/yaws,jgrinstead/yaws,jgrinstead/yaws,jgrinstead/yaws,jgrinstead/yaws,jgrinstead/yaws