Toplevel test task uses the same rake it was invoked with

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8432 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

Rakefile

@@ -15,7 +15,7 @@ task :default => :test
   desc "Run #{task_name} task for all projects"
   task task_name do
     PROJECTS.each do |project|
-      system %(cd #{project} && #{env} rake #{task_name})
+      system %(cd #{project} && #{env} #{$0} #{task_name})
     end
   end
 end