Subprojects

Hi!
So I'd like to submit this pull request for your consideration, please..
I used to keep you (Geoff, maintainer) up-to-date on this need during the past few weeks.
(We exchanged a few emails.)
-Related Jenkins issue-- https://issues.jenkins-ci.org/browse/JENKINS-17872

The 2 commits that matter for this contribution below are 944b299 and 00dd872.
I hope the other commit (d8362dd) does not bother you too much; it is a needful merge so far to my understanding.
I recall Geoff telling me about becoming a committer or so.
-Is that still your intention, and if so, how would you like to proceed further?
Thx & Regards,
Marco =)