Adding AREYOUTHERE to memcached

[christopher at baus.net]

After looking around at the C client last night, I was wondering if it
might be useful to add an AREYOUTHERE command to the protocol.  I want to
be able to check the status of the servers when my app starts up.

What I am thinging is something like:

if(mc_server_available("127.0.0.1", "11211")){
  mc_server_add(mc, "127.0.0.1", "11211");
}

Where mc_server_available sends the AREYOUTHERE command if it is able to
connect to the server.

Again it could be that I'm just missing something in the API.  Also maybe
a similar API could be added with out reving the protocol.

Thoughts?