On-tree recipes that depend on cffi:
- argon2_cffi_bindings
- bcrypt
- pycares
- pynacl
So we're doing the same on those too in one go.
Also:
- moved all recipes to use build/installer instead of setup.py.
- fixed calling of tests on cffi.
x86_64 is used as a baseline: the "x86_64" entry, whatever status it has,
is transformed into "all", and then the other entries in ARCHITECTURES
either dropped or rearranged appropriately.