merge congratulations screen into regular studyoptionsfragment

As per the forum, I'd like to merge this into 2.2 as a one-time-exception to the feature freeze.
Please don't upload the apk to Google Play immediately so that we can test it a bit first.

I've also removed the special nexus 7 landscape layout as per Issue 2161...

![untitled](https://cloud.githubusercontent.com/assets/2818274/3371979/c8f6444c-fba6-11e3-84b9-5bd26ff7b8f0.png)