Allow modifying the hosts list of the SSH provider programatically

[idanarye]

The SSH provider reads the list from ~/.ssh/config. This can be very limiting when the list of remote machines you need to work with changes dynamically (some cloud workflows), or when ~/.ssh/config is mostly rules on patterns rather than a single concrete hostname per entry.

It would be nice if we could have a Lua API to change that list on the fly.

[miversen33]

Duplicate of #87

You're absolutely right. Its on my list, just have some bigger fish to fry first :)