Density graph


git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26191 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
mini/maxi version


git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26192 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e