fix (-T, --tasks) show tasks

minirake

@@ -315,7 +315,7 @@ class RakeApp
 
   # Display the tasks and dependencies.
   def display_tasks
-    Task.tasks.each do |t|
+    MiniRake::Task.tasks.each do |t|
       puts "#{t.class} #{t.name}"
       t.prerequisites.each { |pre| puts "    #{pre}" }
     end
@@ -417,4 +417,4 @@ end
 
 if __FILE__ == $0 then
   RakeApp.new.run
-end
+end