Version 0.2.1
* Added CommandNotFound and ExitCondition to the public interface
* Removed wait lock
* Made more resilient to failure in thread starts
* Corrected os.wait bug

Version 0.2.0 - 10/11/05 21:03
* Corrected horrible race that occurred when two separate threads
  attempted to os.waitpid() at the same time

Version 0.1.0 - 10/11/05 21:03
* Changed status return format to class instances
