tree-wide: remove Emacs lines from all files This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.

nspawn: userns and unified cgroup: chown cgroup.events When starting a container in a new user namespace, systemd-nspawn chowns the cgroup knob files so they are usable by the container. But the cgroup knob file "cgroup.events" was missing. This file exists when the unified hierarchy is used.

util-lib: split out allocation calls into alloc-util.[ch]

util-lib: split out fd-related operations into fd-util.[ch] There are more than enough to deserve their own .c file, hence move them over.

util-lib: split our string related calls from util.[ch] into its own file string-util.[ch] There are more than enough calls doing string manipulations to deserve its own files, hence do something about it. This patch also sorts the #include blocks of all files that needed to be updated, according to the sorting suggestions from CODING_STYLE. Since pretty much every file needs our string manipulation functions this effectively means that most files have sorted #include blocks now. Also touches a few unrelated include files.

nspawn: remove nspawn.h, it's empty now

nspawn: split out cgroup related calls into nspawn-cgroup.[ch]