[Merge] ~ddstreet/software-properties:lp645404 into software-properties:ubuntu/master

[Dan Streetman]

RFC, in-progress git repo
-- 
https://code.launchpad.net/~ddstreet/software-properties/+git/software-properties/+merge/367276
Your team Ubuntu Core Development Team is requested to review the proposed merge of ~ddstreet/software-properties:lp645404 into software-properties:ubuntu/master.