Relocation of the old version of Sokoban

The old version of Sokoban has been moved to the online games quarter requiring the java plugin.

I'm going to enrich the mind games quarter with javascript games that run without any add-on on all recent browsers.

The latest version of Sokoban is here:
https://www.arcadevillage.com/amgq.html

Soon, we will learn together how to create javascript games from scratch.