Fading for infinite cone

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@33957 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Fading for infinite cylinder

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@33958 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Better and simpler code

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@33959 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e