JSON output for rrdtool (XPORT mod)

Hey everyone. I've been playing with some javascript graphing ideas. I
was taking XPORT output and transforming it into json. I was forwarded
an email from this list
(http://oss.oetiker.ch/rrdtool/forum.en.html#nabble-td3575399), and
chatting with some folks in #ganglia. After poking around the source,
I realized it would be pretty easy to have rrdtool spit out json (in
the format I was looking for). After a little hacking, I came up with
this patch:

http://gist.github.com/614476

I'm not suggesting it go in as is - I don't know anything about how
you all handle development, etc. I just wanted to start a discussion
about the merits of this - and my approach thus far.