Support testing Phabricator patches from cmdline
See https://bugs.kde.org/show_bug.cgi?id=402538, Nate gives a very useful example of a developer aid we could provide, e.g.:
kdesrc-build konsole --patch D17643 --include-dependencies --stop-on-failure
Some questions as always (e.g. whether and when to revert the patch) but could be an easy win.