This is a simple GNOME SSH passphrase grabber. To use it, set the
environment variable SSH_ASKPASS to point to the location of
gnome-ssh-askpass before calling "ssh-add < /dev/null".

There is only two run-time options: if you set the environment variable
"GNOME_SSH_ASKPASS_GRAB_SERVER=true" then gnome-ssh-askpass will grab
the X server. If you set "GNOME_SSH_ASKPASS_GRAB_POINTER=true", then the
pointer will be grabbed too. These may have some benefit to security if
you don't trust your X server. We grab the keyboard always.
