[COOK-3472] Cgi support for newer versions of munin ( > 2 ) and nginx 

I spent some time figuring out a rilable way to make munin work in cgi mode. At the moment only nginx is support, but it should be relatively trivial to add Apache. Maybe I will do it later, but pull requests are always welcomed.

Tested on Ubuntu 12.04. By the way if you a wondering how to use most recent version of munin on 12.04 you should check out Ubuntu launchpad. 

With chef you can do it this way:

```ruby
include_recipe "apt"

apt_repository "munin-ppa" do
  uri "http://ppa.launchpad.net/tuxpoldo/munin/ubuntu"
  distribution node['lsb']['codename']
  components ["main"]
  keyserver "keyserver.ubuntu.com"
  key "D294A752"
  deb_src true
end

apt_preference "munin" do
  glob "munin*"
  pin "release o=LP-PPA-tuxpoldo-munin"
  pin_priority "991"
end

include_recipe "munin::server"
```

That's about it. 

Quick note about ppa's - there is no guarantee of what kind of software you install. You need to be very careful choosing one for yourself.