sysusers: fix selinux context of backup files

Also, fix fopen_temporary_label to set proper context. By chance,
all users so far used the same context, so the error didn't matter.

Also, check return value from label_init().

https://bugzilla.redhat.com/show_bug.cgi?id=1121806
update-done: set proper selinux context for .updated

https://bugzilla.redhat.com/show_bug.cgi?id=1121806
Add IFLA_VTI defines to missing.h
configure: add -Wno-typedef-redefinition

Message-ID: <CAJ+BJsz9Qy-JU25dUuGT2n0LMNzcOpoJNGNtbf_boSuT_6hONw@mail.gmail.com>
Merge systemd-verify with systemd-analyze
shell-completion: systemd-analyze verify, systemctl link

Some zsh completion helpers were not installed, so completion
was broken.

Add systemd-analyze verify. Make systemctl link complete only
unit names.
man: merge systemd-verify with systemd-analyze
nss-myhostname: don't include assert.h twice
resolved: rework logic so that we can share transactions between queries of different clients
resolved: implement negative caching
resolved: most DNS servers can't handle more than one question per packet, hence let's not generate that
update TODO
networkd: set route protocol

All routes added by networkd are currently set RTPROT_BOOT, which according
to the kernel means "Route installed during boot" (rtnetlink.h).  But this
is not always the case as networkd changes routing after boot too.  Since
the kernel gives more detailed protocols, use them.

With this patch, user-configured static routes now use RTPROT_STATIC (which
they are) and DHCP routes use RTPROT_DHCP.  There is no define for IPv4LL
yet, so those are installed as RTPROT_STATIC (though perhaps RTPROT_RA is
better?).

[tomegun: fixup
src/network/networkd-link.c:972:33: error: too few arguments to function 'route_new_dynamic']
dhcp-network: remove unused DHCP6_STATE_RS

Probably a left-over from when router solicitations were
requested in the DHCP6 code.  But since they are now separate,
this state is no longer needed.
Merge remote-tracking branch 'upstream/master'