Update Shapeways button flow

- Change Shapeways icon to "3D"
- Add disclaimer step to Shapeways button flow

![image](https://cloud.githubusercontent.com/assets/206973/5309481/c1ff58d2-7bd9-11e4-85d7-e6eca0d2013c.png)

http://screencast.com/t/ItydHfN3
intentional that we toggle here instead of hide/show.  Also, is this the first time we use jquery in blockly?