Re #426 - Collection Days: Previous, without content

* re-factored leaflet map so that europeana controls and minimap are not the default and the google map layer is only added when the europeana ctrl is added to the map
* adjusted the collection day show so that it is more generic and handles the possible states:
  - upcoming collection day
  - collection day without stories entered yet
  - collection day with storeis entered
  - matched the ui design as much as possible
* added localeapp message keys