restored ability of annotate_models to run as a plugin.

lib/tasks/annotate.rake

+def is_plugin?
+  (defined? ANNOTATE_MODELS_PREFS::USE_PLUGIN) && 
+      (!ANNOTATE_MODELS_PREFS::USE_PLUGIN.nil?) ? 
+      ANNOTATE_MODELS_PREFS::USE_PLUGIN : false
+end
+
 desc "Add schema information (as comments) to model and fixture files"
 task :annotate_models => :environment do
-  require 'annotate_models'
+  if is_plugin?
+    require File.expand_path(File.dirname(__FILE__) + '/../annotate/annotate_models')
+  else
+    require 'annotate_models'
+  end
+
   options={}
   options[:position_in_class] = ENV['position_in_class'] || ENV['position']
   options[:position_in_fixture] = ENV['position_in_fixture'] || ENV['position']  
@@ -10,6 +21,10 @@ end
 
 desc "Remove schema information from model and fixture files"
 task :remove_annotation => :environment do
-  require 'annotate_models'
+  if is_plugin?
+    require File.expand_path(File.dirname(__FILE__) + '/../annotate/annotate_models')
+  else
+    require 'annotate_models'
+  end
   AnnotateModels.remove_annotations
 end
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