[update] update to upstream 47258c58
Squashed 'qtsystems/' changes from 762581e..47258c5

47258c5 Fix up some of these best guesses.
2250aa3 Remove unnecessary dependency to qtjsbackend from sync.profile
e1b6ee9 try harder to find unique ID, and validate it against QUUid.
db68283 Fix warning found by clang: private unused members in a class
2cb6b74 make signals work on mac
0b220b2 Disable tests failing on Windows.
46b3203 Stabilize qservicemanager_ipc.
f71976f doc: Eliminate even more cases of multiple topic commands

git-subtree-dir: qtsystems
git-subtree-split: 47258c5861ee05e1f550200f3b65191b3897fb3a
Merge commit 'fcd13bccc8ca1aa23ace6061bb262babc1cb8012'