fix dilate cone/cylinder

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@36548 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
snap to grid for extrusion tools

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@36549 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e