stacked.php graphs don't properly stack

[cddude229]

In stacked.php, the graphs don't properly stack. This is caused by off by one errors. What happens is "item1" and "item2" both use item1's value, and then "item3" uses item2's value. This is the diff of my fix:

74c74
< $c = 1;

---
> $c = 2;
77c77
<     $cx = $c/(1+count($hosts));

---
>     $cx = ($c-1)/(1+count($hosts));
87c87
< $c = 1;

---
> $c = 2;

I don't have the time to fork and submit a pull request unfortunately, sorry.