Changed the style of the info box. Also added a show/hide button for the box.
Fixes minor indentation issue.
Changed the title for the Zollner illusion.
Factored out some redundant math from the inner for-loop.
Made the canvas responsive to changes in window size. (TODO: Apply this change to the other canvas demos.)
Removed redundant code associated with clearCanvas().
Fixed more indentation issues because on long flights, one has to find ways to cope.