Interactive Documentation (#416)

I gave interactive documentation another try after you fixed #407. This time it did not crash, but there are still some problems:

- In "output file", I entered "y:\cloud" and expected it to generate the documentation in that folder. Instead it generated the documentation in the root of "y:".

- I wanted to enter a folder + file name next, but now when I type in the "output file" textbox, the cursor moves to the start of the word after every key that I type.

- In the generated documentation, the links directly below the preview thumbnails of my diagrams work, but clicking on the thumbnail image has no effect.

- When I have diagrams with longer names, the names overlap in the diagram thumbnails list.

I used that feature more out of curiosity than for any real purpose, so I don't need fixes for these bugs. I just wanted to let you know about them.