Add documents to site payload

lib/jekyll/document.rb

@@ -228,5 +228,14 @@ module Jekyll
       path <=> anotherDocument.path
     end
 
+    # Determine whether this document should be written.
+    # Based on the Collection to which it belongs.
+    #
+    # True if the document has a collection and if that collection's #write?
+    #   method returns true, otherwise false.
+    def write?
+      collection && collection.write?
+    end
+
   end
 end

lib/jekyll/site.rb

@@ -325,6 +325,7 @@ module Jekyll
           "categories"   => post_attr_hash('categories'),
           "tags"         => post_attr_hash('tags'),
           "collections"  => collections,
+          "documents"    => documents,
           "data"         => site_data
         }))
       }