Fix some translations. Improve style for menu, fix layout in digitals page. Working version.

app/views/spree/admin/digitals/index.html.erb

@@ -8,10 +8,10 @@
   <% end %>
 
 <% else %>
-  This product has no variants.
+  <%= Spree.t :product_without_variants %>
 
  <% if @product.master.digital? %>
-    A digital version of this product currently exists:
+    <%= Spree.t :digital_exists %>
     <%= render @product.master.digitals %>
   <% end %>