Add param for KexAlgorithms, Ciphers

[adritium]

The hack I currently use is: select param ssh_command and set its value ssh -oKexAlgorithms=diffie-hellman-group1-sha1 -oCiphers=aes128-cbc

This results in the sshfs.exe command having -ossh_command=ssh -oKexAlgorithms=diffie-hellman-group1-sha1 -oCiphers=aes128-cbc