Add Views Grid Three and Views Grid Two classes

[aaroncole]

The .views-grid-n layout options are awesome. Having the ability to create two and three column grids in the same manner would be even awesomer! Is there any reason not to?

[meganem]

You are correct! We should add those in. Just takes writing the code for those.
You want to share yours? Feel free to paste into the comments here, or do a more formal pull request if you like.