Deleting old PNGs

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@37300 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
More PNGs deleted

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@37301 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e