Fix for #2960

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@22947 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Alleged speedup in Web: take the Graphics view into two parts: foreground and background (this can later enhanced by taking the foreground into two parts too)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@22948 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e