New Nodebox Icon

Here's a suggestion for the new NodeBox icon. The icon was created by @lucasnijs.

![Screen Shot 2013-04-24 at 09 42 15](https://f.cloud.github.com/assets/8477/418685/8a1308f8-acb2-11e2-9932-e8363e87393f.png)

![windows-taskbar](https://f.cloud.github.com/assets/8477/418674/31c3dc18-acb2-11e2-80b0-d53b3600313a.png)