Google Code-in

Rewrite the Abacus activity for Sugarizer. Abacus activity is an activity to explore the way of compute and represent numbers using different mechanical counting systems - Abacus - developed by the ancient Romans and Chinese.

Use same icons and drawing than the Python version of the activity.

The new activity should really work as Sugarizer activity: icon must change color, STOP button should work (go back to Sugarizer homeview).

The activity should be responsive: board should adapt to the size of the browser.