o adds ECDSA keys and host key support when using OpenSSL
 o adds ED25519 key and host key support when using OpenSSL 1.1.1
 o adds OpenSSH style key file reading
 o adds AES CTR mode support when using WinCNG
 o adds PEM passphrase protected file support for Libgcrypt and WinCNG
 o adds SHA256 hostkey fingerprint
 o adds libssh2_agent_get_identity_path() and libssh2_agent_set_identity_path()
 o adds explicit zeroing of sensitive data in memory
 o adds additional bounds checks to network buffer reads
 o adds the ability to use the server default permissions when creating sftp directories
 o adds support for building with OpenSSL no engine flag
 o adds support for building with LibreSSL
 o increased sftp packet size to 256k
 o fixed oversized packet handling in sftp
 o fixed building with OpenSSL 1.1
 o fixed a possible crash if sftp stat gets an unexpected response
 o fixed incorrect parsing of the KEX preference string value
 o fixed conditional RSA and AES-CTR support
 o fixed a small memory leak during the key exchange process
 o fixed a possible memory leak of the ssh banner string
 o fixed various small memory leaks in the backends
 o fixed possible out of bounds read when parsing public keys from the server
 o fixed possible out of bounds read when parsing invalid PEM files
 o no longer null terminates the scp remote exec command
 o now handle errors when diffie hellman key pair generation fails