added zoom patch from:

http://aprilmayjune.org/2009/09/16/collectd-drrawcgi-zoom-into-your-graphs-like-you-used-to-with-cacti/

drraw% patch < drraw.cgi.zoom_patch
Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|--- drraw.cgi  2009-02-27 18:49:01.000000000 +0100
|+++ drraw.cgi_patched  2009-09-16 20:02:51.000000000 +0200
--------------------------
Patching file drraw.cgi using Plan A...
Hunk #1 succeeded at 31.
Hunk #2 succeeded at 365.
Hunk #3 succeeded at 4018 (offset 4 lines).
done
drraw.cgi before zoom patch
from

http://aprilmayjune.org/2009/09/16/collectd-drrawcgi-zoom-into-your-graphs-like-you-used-to-with-cacti/
added README for fork