Completed, Successful & Stable using Enum

[JENKINS-16301] Replace impl of getDigestOf with standard (Commons Codec) DigestUtils.md5Hex, for simplicity.

[JENKINS-15652] Include directory in assertion messages so it is possible to tell which project is broken.

It looks like our tests are getting bigger to the point that it needs
more PermGen space. Use fork and run with a bigger perm gen size to get
going.

Amends lvotypko’s 33e0df78 to be as careful as bdff4254 + f65da7f9 + 10e9b002 for persistent actions.

Based on the work of Michael Elkin [1].

[1] https://issues.jenkins-ci.org/secure/attachment/20588/0001-tag-1.414-for-parameters-in-multiconfig-filters.patch