fix bug:no such file to load -- annotate/annotate_models (LoadError) for annotate command

lib/tasks/annotate_models.rake

 desc "Add schema information (as comments) to model and fixture files"
 task :annotate_models => :environment do
-  require 'annotate/annotate_models'
+  require File.join(File.dirname(__FILE__), '..', 'annotate/annotate_models')
   options={}
   options[:position_in_class] = ENV['position_in_class'] || ENV['position'] || :before
   options[:position_in_fixture] = ENV['position_in_fixture'] || ENV['position']  || :before
@@ -14,7 +14,7 @@ end
 
 desc "Remove schema information from model and fixture files"
 task :remove_annotation => :environment do
-  require 'annotate/annotate_models'
+  require File.join(File.dirname(__FILE__), '..', 'annotate/annotate_models')
   options={}
   options[:model_dir] = ENV['model_dir']
   AnnotateModels.remove_annotations(options)