goBack framework implemented

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26693 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
goBack framework implemented

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26694 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
More save GUI

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26695 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e