Triangle fan detection

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34250 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
for browsers that don't support TRIANGLE_FAN

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34251 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e