EPE-85 Convert Workunit List to Historic Tree

Fixes EPE-85
Fixes EPE-27

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #133 from GordonSmith/EPE-27-29_ReworkWUList

EPE-85 Convert Workunit List to Historic Tree

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>