Ticket #3767: fixing a problem with app.html, the Graphics view 2 shown and closed by X sign (Graphics view 1 not updated)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30972 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
polygon triangulation (step 3)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30973 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e