[Feature request] Allow passing the DISPLAY environment variable to ssh via command-line option

[ramilehti]

Sometimes it is useful that the ssh forwards the X11 connection. For example when you have to run sudo on the remote host using ssh-askpass. You shouldn't have to configure sudo to not ask a password and using ssh-askpass from within the rsync ssh connection has been a useful way of doing it.
Consider the following command-line for example
rsync -vaPr -e 'ssh -X' --rsync-path="SUDO_ASKPASS=/usr/bin/ssh-askpass sudo -A rsync" remote-host:/var/backups/ local_backup/
With this command line you can make a copy of files that require privileged access by authenticating through sudo.

I understand that by default forwarding the X11 connection is not useful or desirable, but you should have the option to do so.
For examples --pass-display or similar.