Extracted `aggregate_post_info` from site.rb into reader.rb

- Extracted
  - Updated References
  - Ran Tests

Signed-off-by: Martin Jorn Rogalla <martin@martinrogalla.com>

lib/jekyll/reader.rb

@@ -122,5 +122,14 @@ module Jekyll
       name.gsub!(/(^|\b\s)\s+($|\s?\b)/, '\\1\\2')
       name.gsub(/\s+/, '_')
     end
+
+    # Aggregate post information
+    #
+    # post - The Post object to aggregate information for
+    #
+    # Returns nothing
+    def aggregate_post_info(post)
+      site.posts << post
+    end
   end
 end

lib/jekyll/site.rb

@@ -178,7 +178,7 @@ module Jekyll
       posts = reader.read_content(dir, '_posts', Post)
 
       posts.each do |post|
-        aggregate_post_info(post) if publisher.publish?(post)
+        reader.aggregate_post_info(post) if publisher.publish?(post)
       end
     end
 
@@ -193,7 +193,7 @@ module Jekyll
 
       drafts.each do |draft|
         if draft.published?
-          aggregate_post_info(draft)
+          reader.aggregate_post_info(draft)
         end
       end
     end
@@ -355,15 +355,6 @@ module Jekyll
       end
     end
 
-    # Aggregate post information
-    #
-    # post - The Post object to aggregate information for
-    #
-    # Returns nothing
-    def aggregate_post_info(post)
-      posts << post
-    end
-
     def relative_permalinks_deprecation_method
       if config['relative_permalinks'] && has_relative_page?
         Jekyll::Deprecator.deprecation_message "Since v2.0, permalinks for pages" +