Cube Support

Just wanted to request support for the cube format.  This is a perfect place to keep track of cubes.  Along with that, more generically it would be nice to be able to export a list of the cards I'm missing or just see a count like I have 543/720 cards in my inventory or something.

I'm not sure what else would be useful besides recognizing a range of at least 360 cards as a cube, but I'm sure other people have ideas or opinions.