Add proposed shareable byte vector interface.
Add proposed shareable byte vector interface.

dochang/cffi,akovalenko/cffi,3b/cffi,cffi/cffi,3b/cffi,kingcheez/cffi-cheez,wesen/cffi,dochang/cffi,akovalenko/cffi,attila-lendvai/cffi,wesen/cffi,wesen/cffi,akovalenko/cffi,cffi/cffi,marsijanin/cffi,dkochmanski/cffi,mcna/cffi,dkochmanski/cffi,marsijanin/cffi,dkochmanski/cffi,marsijanin/cffi,stassats/cffi,stassats/cffi,stassats/cffi,kingcheez/cffi-cheez,dochang/cffi,attila-lendvai/cffi,mcna/cffi,3b/cffi,kingcheez/cffi-cheez,cffi/cffi