Integrate with Uniswap for instant exchange between popular tokens

[lsaether]

This is a longer term idea that will be good to do.

Uniswap (https://github.com/Uniswap) is basically a decentralized, permissionless ShapeShift for ethereum. One of the coolest things about shapeshift (imo) was the shifty button which anyone could copy-paste into their page. I don't think we should build a Uniswap button per se, but perhaps integrate it into one of the screens of our DApp with maybe just the basic functionality of once click exchange between ether and Dai. As we expect some economies will be using ether as the reserve, and others will be using dai, this seems like a good idea