Collates some figures, about the for CO2 per GB transferred/downloaded on the internet

[mrchrisadams]

I've found the figures for this now, or at least ones I feel okay about using, which I'll add to this issueon the weekend.

Now we need a fun little slider to quickly give people a way to track the impact of use for the 'packet's part of using digital products.

If I mention mozsprint, presumably it appears in this link