Connection with Key Authentication and SSH proxy server.

[goodwilling]

Hi. Thanks for the excellent work. I have two feature requests for the vfsjfilechooser2:
It is strongly desired that the remote host can be connected via SSH Key Authentication. Also, support for SSH proxy server is also grateful.

[fracpete]

I'm not actually the author of the library, I merely resurrected it, so I don't really know how the file name resolution works in practice (another Apache library does that). Also, I haven't used the library myself for years. Only a recent PR breathed some life into it again.