All Workloads must be named do_*.  Workloads should be named "do_*_loop"
if they run continuously until killed.

A given workload can have dependencies above and beyond xdiagnose
itself, but must include functionality to test and install what it
needs.  In general workloads should strive to not require any packages
which are not available in the Ubuntu main, universe, or multiverse
archives.

Workloads should take a command as first argument:
  info    - Returns a string documenting the workload and its prerequisites
  depends - Returns a list of prerequisite packages this workload requires
  check   - Test if prerequisites are satisfied
  setup   - Set up working directories, etc.
  once    - Execute the process one time only
  run     - Execute the process in a loop indefinitely


Dependencies
------------
wmctrl
