Various updates + final things to be done on tutorial

Hi Eduard,

Great work on the tutorial. I polished it a bit more and I'd say it's pretty much good-to-go. Which is nice, because I plan on releasing 2.9.0 soon.

Some final things to be done:

- Update `FigInterface` with the interface as it is *by default* on the first start of OpenSesame, i.e. with the debug window visible, the file pool hidden, and the item toolbar on the left. You can reset OpenSesame by starting it with the `--start-clean` parameter.
- Fix file formats for snapshots. It looks like you have renamed `.opensesame.tar.gz` files to `.opensesame`, but they are very different formats! One is a `.tar.gz` archive, the other is a plain-text file. So please change this so that all `.opensesame` files are actually in `.opensesame` format.

Finally, make sure you don't commit files that don't belong in the repository. You committed `yrnaydd3.mt4.txt`, which looks like some kind of personal note.

Cheers!  
Sebastiaan