New icons for new open screen in web

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35473 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
new OpenScreen

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35474 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e