add example data cube about mortalities in europe (estimated values)

sources:
- united kingdom: http://www.indexmundi.com/g/g.aspx?c=uk&v=26
- germany: http://www.indexmundi.com/g/g.aspx?c=gm&v=26
Fix missing cache dir check
mortalityEurope: Small corrections and add sameAs relation
add example data cube about populations in europe (estimated values)
Fix small break in json encoded configuration for ui