Speed: potentially integrate multiple find calls and (maybe) do away with grep.

[gdevenyi]

ssh-find-agent is 50% of my shell startup time

Clearly a lot of time is spent at
https://github.com/wwalker/ssh-find-agent/blob/master/ssh-find-agent.sh#L76-L84

Where find is called multiple times against multiple paths.

I think we can do better:

1. Use the -o syntax of find, https://superuser.com/questions/1494617/what-is-the-o-argument-in-find-command
2. Potentially adjust the existing find calls to do away with the post-grep (although you can instead combine the grep into a single one)

I'm going to look into how this works, but find is black magic and difficult, so I'm stating my intention here.

[wwalker]

I pushed a possible fix to 56-draft. I'll use it a few days and see where it leads.

[wwalker]

@gdevenyi

For me, with 12 live ssh-agent sockets, running time ssh-find-agent yields ~80 to 120 ms. If it takes significantly longer for you, I suspect that you will find the actual time is being spent in line 90 talking to dead sockets.