Version 0.5:
- Added the msmtp-listqueue.sh script, contributed by Andreas Kneib.

Version 0.4:
- Frank Thieme sent the following improvements:
  - msmtp-runqueue.sh now uses a lock file to prevent two instances of the
    script from running simultaneously.
  - msmtp-enqueue.sh now checks if you're online, and calls msmtp-runqueue.sh
    immediately if this is the case.
    This functionality is commented out; you have to adapt the online check to
    your system before activating it.