Please add new user format #{lastname}.

Calling by a last name is more common in a Japanese company than calling by a first name.

Index: app/models/user.rb
===================================================================
--- app/models/user.rb  (revision 9651)
+++ app/models/user.rb  (working copy)
@@ -32,6 +32,7 @@
     :firstname => {:string => '#{firstname}', :order => %w(firstname id)},
     :lastname_firstname => {:string => '#{lastname} #{firstname}', :order => %w(lastname firstname id)},
     :lastname_coma_firstname => {:string => '#{lastname}, #{firstname}', :order => %w(lastname firstname id)},
+    :lastname => {:string => '#{lastname}', :order => %w(lastname id)},
     :username => {:string => '#{login}', :order => %w(login id)},
   }