`highlight-presentation` in puzzle demo breaks Demo Driver
The issue was introduced by a partial fix for #17 (closed) in commit 477977a9.
For some reason, defining highlight-presentation
presentation method for puzzle-cell
type causes Demo Driver to break when you mouse-over any demo on the list, with condition about unknown type specifier. I've disabled the definition of that presentation method in code for now, but this needs to be fixed at some point.