Cluster support patch

[Dave McAnulty]

Hello all,

I created a small patch (attached) to support 'clusters' in slack. This patch allows for:

roles.conf

www5:  webserver special

www:   webserver 

www15  webserver special.super 

specifiying the --hostname is another option, but is very tedious and dangerous (if you ever forget).

This simplifies your conf and the other cool advantage is you can add www55 and not have to modify your slack conf.

I've done some very basic testing and it works in my environment, your mileage may vary, Please let me know what you guys think, and if you end up using the patch :D