Merge pull request jekyllt#16 from sanchez2210/autgenerator-by-author

Make AutGenerator get posts by author.

_plugins/jekyll-autgenerator.rb

@@ -5,8 +5,9 @@ class AuthorsGenerator < Generator
     safe true
 
     def generate(site)
-      site.categories.each do |author|
-        build_subpages(site, "author", author)
+      site.data['authors'].each do |author, data|
+        posts = [author, posts_by_author(site, author)]
+        build_subpages(site, 'author', posts)
       end
     end
 
@@ -36,6 +37,12 @@ def paginate(site, type, posts)
 
       end
     end
+
+    private
+
+    def posts_by_author(site, author)
+      site.posts.docs.select { |post| post.data['author'] == author }
+    end
   end
 
   class GroupSubPageAuthor < Page