Make geofront ssh compatible to ssh command

[dahlia]

Feedback from @serialx.

The geofront-cli ssh command currently takes the remote alias instead of its actual DNS/IP address. It makes hard to use geofront-cli ssh command as a drop-in replacement of the existing ssh command.

[achimnol]

Just a reminder: My PR #11 also improves this by adopting the concept of command templates for ssh/scp commands. It already adds the support of -i (custom identity) and -D (socks proxy) options, and other options could be added with ease.