* Remove the stream ciphers
The unauthenticated stream ciphers (aes-*-cfb, aes-*-ctr, camellia-*-cfb,
chacha20, chacha20-ietf, salsa20) are gone from every build, together
with the SS_ENABLE_LEGACY option, the C++ stream codecs, their C test
oracle and the stream-only tests and configurations. A configuration
naming one of them, or RC4/table, now fails at startup with a message
pointing to an AEAD method, and test_cli checks that.
Shell completions list only the supported methods (and now include the
2022 ones), and the docs and the compatibility contract say the stream
ciphers were removed.
* Drop the Mbed TLS CFB requirement and stale stream-cipher examples
CFB was only needed by the removed stream ciphers, so a system Mbed TLS
built without it no longer fails to configure. The public header example
now uses aes-256-gcm.
Max Lv
f1f31c3c05