Add ability to use paswordless logins

[vladsharp]

Example: You have a shell account on example.com. You
have generated a set of keys (ssh-2 rsa for example)
and uploaded the public key to example.com and added it
to the list of trusted keys so you will be able to
login without a password. Private key caching
facilities are already available on Windows and Linux,
such as Pageant or the keychain tools.

PuTTy already implements this (to take an example). It
would be nice if you could specify a public key.

Thanks.
Vladimir

[Tim Kosse]

Since the sftp support in FileZilla is based on PuTTY, the
peagent tool from putty is supported as well.