Create a demo

[smnbbrv]

Problem
Because of cross-platform drag-drop things the automated testing for this project is close to impossible (even the original library does not have it) and most likely does not worth the effort. That is why I am always forced to test everything on my projects; nearly every change can lead to unpredictable behaviour thus it is hard to maintain the project.

Solution
Adding a demo which will solve the problem above (at least partly) and meanwhile will make it easier to see the library in action.

[smnbbrv]

done