Replace diagram with updated version

Replace the diagram on the 'What do I need to do?' page and Upload page (it's within the expandable section titled 'Which version should I upload?') with the attached, updated image.
![infographic-update-light-grey-with-orange-aam](https://cloud.githubusercontent.com/assets/1784932/2959378/4d837baa-dab2-11e3-8e9d-0c4d5b00918b.png)