doc: correct punctuation and improve typography in documentation

man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.

man: generate configured paths in manpages In particular, use /lib/systemd instead of /usr/lib/systemd in distributions like Debian which still have not adopted a /usr merge setup. Use XML entities from man/custom-entities.ent to replace configured paths while doing XSLT processing of the original XML files. There was precedent of some files (such as systemd.generator.xml) which were already using this approach. This addresses most of the (manual) fixes from this patch: http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/patches/Fix-paths-in-man-pages.patch?h=experimental-220 The idea of using generic XML entities was presented here: http://lists.freedesktop.org/archives/systemd-devel/2015-May/032240.html This patch solves almost all the issues, with the exception of: - Path to /bin/mount and /bin/umount. - Generic statements about preference of /lib over /etc. These will be handled separately by follow up patches. Tested: - With default configure settings, ran "make install" to two separate directories and compared the output to confirm they matched exactly. - Used a set of configure flags including $CONFFLAGS from Debian: http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/rules Installed the tree and confirmed the paths use /lib/systemd instead of /usr/lib/systemd and that no other unexpected differences exist. - Confirmed that `make distcheck` still passes.

man: use utf-8 in systemd-remount-fs.service(8)

man: fix a bunch of links All hail linkchecker!

Reindent man pages to 2ch

man: add various filenames to the index Everything which is an absolute filename marked with <filename></filename> lands in the index, unless noindex= attribute is present. Should make it easier for people to find stuff when they are looking at a file on disk. Various formatting errors in manpages are fixed, kernel-install(1) is restored to formatting sanity.

man: link in API FS documentation from the wiki

man: reword man page titles Make sure the man page titles are similar in style and capitalization so that our man page index looks pretty.

remount-fs: also remount /usr according to fstab

man: document systemd-remount-fs.service