Without looking to much into the technical details of this patch,
- it should master first (and then be backported to dunfell)
- the patches to need an Upstream-Status field
- changes should be brought to upstream first (and if rejected then a
proper explanation has to be provided in the patch
From: Pavel Zhukov
Using systemd notify, a service dependency would be more robust. This
allows, for example, another service to depend on weston-init without
having to hack a sleep (or similar). This change required more robust
handling of weston modules argument due to custom argument parser
