tooltips for the individual bars of AlgoBarChart

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35205 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
better behavior for OS X spreadsheet file chooser 

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35206 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e