User#<=> modified to sort on firstname if same lastname

git-svn-id: http://redmine.rubyforge.org/svn/trunk@446 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/user.rb

@@ -143,7 +143,7 @@ class User < ActiveRecord::Base
   end
 
   def <=>(user)
-    lastname <=> user.lastname
+    lastname == user.lastname ? firstname <=> user.firstname : lastname <=> user.lastname
   end
   
 private