Submenu opens, if the bottom half of button clicked. (#4134)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@32610 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Some cleaning. (#4134)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@32611 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e