Add small popup windows for source material

See merge request !2

Optimization: data is now checked for consistency once at import, instead of multiple times during the reasoning process.

refactoring: instead of two sets for the results (original results and inferred results), there is now only one set that contains both the original and the inferred results. Also, parameters are stored as tuples now, not as lists.

Kleiner Geschwindigkeitsfix

See merge request !1