Debugging code left in 6.x-1.x-dev feb 22

Issue Summary

First off, thanks for your great work on this module!

However, I've had a terrible time with CRON failing ("Cron run exceeded the time limit and was aborted."). For a long time I thought it was either the Notifications or Messaging module, as those are where the CRON run was coming from and if I turned either one off, CRON ran fine.

However, I have traced my problem all the way back to some debugging code left in mimemail at line 502:

    print_r($key); die;

When I comment this out, it works fine.

Jeff