[sr-dev] Modules linking with OpenSSL

I created another module that links with OpenSSL.

The current list of (non-obsolete) modules that link with OpenSSL is: - websocket - auth_ephemeral - tls - stun - outbound - osp - auth_identity

FYI, for the modules I've created the usage of OpenSSL is: - websocket: SHA1() is used to create the key in the WebSocket handshake response. - auth_ephemeral: HMAC(EVP_sha1(), ...) is used to calculate the password based on the username and secret key and openssl/sha.h is included for "#define SHA_DIGEST_LENGTH" - outbound: HMAC(EVP_sha1(), ...) is used to encode the flow token and RAND_bytes() is used to get cryptographically strong pseudo-random bytes for the secret key

- stun: not sure about this as a lot of the code was copied from core