Allow apache to be moved off default 80/443

Hi @echocat,

I really like the work you've done to get graphite up and running on Ubuntu. There was only one slight draw back in my case. I want to use monitoring on a system configured to use Nginx. My solution to this is to optionally allow Apache to use alternative HTTP/HTTPS ports. Is this something you'd be interested in the main project? 

I was wondering if should allow Nginx to be used as an alternative to Apache, but this is proved more work then I can do right now.

All the best,

@oisinmulvihill