build-sys: the pure/const warning options are probably too much as default, but let's make it available via "autogen.sh a"
build-sys: minor fixes found with cppcheck
Revert "journalctl: remove unexpected behavior of journalctl -b"

This reverts commit cf5bccc2bb9569030cb04debbc4208aaca0fe5b4.

We should fix thinks properly if they aren't perfect, not just break
other things...
Revert "completion: don't offer completions for journalctl -b"

This reverts commit c756a6d57cdb678b702c68913dae3e11ff0427ae.
journalctl: make sure -b --foobar cannot be misunderstood as --boot=--foobar
bus: make system bus kdbus node world-accessible
update TODO
bus: don't process Peer interface messages in the proxy
man: resolve word omissions

This is a recurring submission and includes corrections to:
word omissions and word class choice.
man: improvements to comma placement

This is a recurring submission and includes corrections to:
comma placement.
man: grammar and wording improvements

This is a recurring submission and includes corrections to:
- missing words, preposition choice.
- change of /lib to /usr/lib, because that is what most distros are
  using as the system-wide location for systemd/udev files.
Trim TODO
man: document fail/nofail, auto/noauto

Also s/filesystem/file system/ in a few places.