Cider command uses known endpoints

Looking for feedback - please give this a try.

I'm currently a bit stuck in that there is no way to turn off IDO matching against host/label. This needs to be resolved IMO before this PR can be merged.

I'll also get some tests written.

Configure your endpoints like:

(setq cider-known-endpoints '(("Random" "11.254.76.52" "7888")
                              ("123.250.71.56" "7888")))

The label is optional.