common spreadsheet context menu 

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35733 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
web spreadsheet context menu rewritten 

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35734 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e