Added an option to connect through a UNIX socket

[bpiwowar]

This patch adds an option (--unixsocket or -s) to use a UNIX socket rather than a TCP socket. This is useful when the remote host is a shared server.

[sorbits]

Would it make sense to have the socket default to something like $HOME/.rmate.socket?

I’m even inclined to have rmate test if the socket exists, and prefer the unix socket over TCP when it does.

This should solve issue #15.

[bpiwowar]

Yes this would - and it would not break anything anyways. I updated the pull request so that rmate uses ~/.rmate.socket by default if the file exists (it does not check if this is a valid socket though).

[sorbits]

Merged as commit 4a55b26, thanks!

I squashed the two commits into one and fixed a few things: reading the environment variable had a to_i (instead of to_s), there was a debug output line, and I changed the README example to use the default socket path in the setup example.

I have unfortunately not been able to test the functionality, as I do not have any servers with openssh 6.7+.