long long fractionals

I added support for the fixed point type system similar to yours in our out-of-tree branch. I'd like to deprecate mine and adopt yours. One issue we have is that we support "long long" _Fract and _Accum. We can't easily drop support for these types as that would be a customer visible change. Would you accept a patch adding support for these? I could easily put them on a hidden switch or feature option.

+Bevin Hansson