Seems i was the only one who was really up to using it and
i do have gcc-5 finally backported and installed here so
such a fine-tune flags are no longer needed.
It's hopefully no longer needed, at least not needed for as long as
single ptex face corresponds to a single patch which should be always
correct for uniform subdivisions as far as i know.
This includes C-API bindings in intern/opensubdiv and CMAke module
which finds the OpenSubdiv library. This filea are not in use so
far, making it a separate commit to make actual integration commit
more clear.
