dhcp: update systemd DHCP code

This is a direct dump from systemd git on 2014-11-19, git commit
a4962513.  Only relevant files were included.

    SYSTEMD_DIR=../systemd
    COMMIT=a4962513c555fe3ac4b5bebf97a71701361a45b0

    (
       cd "$SYSTEMD_DIR"
       git checkout "$COMMIT"
       git clean -fdx
    )
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp-internal.h ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-internal.h
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp-lease-internal.h ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-lease-internal.h
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp-network.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-network.c
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp-option.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-option.c
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp-packet.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-packet.c
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp-protocol.h ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-protocol.h
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp6-internal.h ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp6-internal.h
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp6-lease-internal.h ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp6-lease-internal.h
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp6-network.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp6-network.c
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp6-option.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp6-option.c
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/dhcp6-protocol.h ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp6-protocol.h
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/network-internal.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/network-internal.c
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/network-internal.h ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/network-internal.h
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/sd-dhcp-client.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-client.c
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/sd-dhcp-lease.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-lease.c
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/sd-dhcp6-client.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp6-client.c
    /bin/cp "$SYSTEMD_DIR"/src/libsystemd-network/sd-dhcp6-lease.c ./src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp6-lease.c
    /bin/cp "$SYSTEMD_DIR"/src/shared/async.h ./src/dhcp-manager/systemd-dhcp/src/shared/async.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/fileio.c ./src/dhcp-manager/systemd-dhcp/src/shared/fileio.c
    /bin/cp "$SYSTEMD_DIR"/src/shared/fileio.h ./src/dhcp-manager/systemd-dhcp/src/shared/fileio.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/list.h ./src/dhcp-manager/systemd-dhcp/src/shared/list.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/macro.h ./src/dhcp-manager/systemd-dhcp/src/shared/macro.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/refcnt.h ./src/dhcp-manager/systemd-dhcp/src/shared/refcnt.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/siphash24.c ./src/dhcp-manager/systemd-dhcp/src/shared/siphash24.c
    /bin/cp "$SYSTEMD_DIR"/src/shared/siphash24.h ./src/dhcp-manager/systemd-dhcp/src/shared/siphash24.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/socket-util.h ./src/dhcp-manager/systemd-dhcp/src/shared/socket-util.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/sparse-endian.h ./src/dhcp-manager/systemd-dhcp/src/shared/sparse-endian.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/strv.c ./src/dhcp-manager/systemd-dhcp/src/shared/strv.c
    /bin/cp "$SYSTEMD_DIR"/src/shared/strv.h ./src/dhcp-manager/systemd-dhcp/src/shared/strv.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/time-util.c ./src/dhcp-manager/systemd-dhcp/src/shared/time-util.c
    /bin/cp "$SYSTEMD_DIR"/src/shared/time-util.h ./src/dhcp-manager/systemd-dhcp/src/shared/time-util.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/utf8.c ./src/dhcp-manager/systemd-dhcp/src/shared/utf8.c
    /bin/cp "$SYSTEMD_DIR"/src/shared/utf8.h ./src/dhcp-manager/systemd-dhcp/src/shared/utf8.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/util.c ./src/dhcp-manager/systemd-dhcp/src/shared/util.c
    /bin/cp "$SYSTEMD_DIR"/src/shared/util.h ./src/dhcp-manager/systemd-dhcp/src/shared/util.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/unaligned.h ./src/dhcp-manager/systemd-dhcp/src/shared/unaligned.h
    /bin/cp "$SYSTEMD_DIR"/src/shared/in-addr-util.c ./src/dhcp-manager/systemd-dhcp/src/shared/in-addr-util.c
    /bin/cp "$SYSTEMD_DIR"/src/shared/in-addr-util.h ./src/dhcp-manager/systemd-dhcp/src/shared/in-addr-util.h
    /bin/cp "$SYSTEMD_DIR"/src/systemd/_sd-common.h ./src/dhcp-manager/systemd-dhcp/src/systemd/_sd-common.h
    /bin/cp "$SYSTEMD_DIR"/src/systemd/sd-dhcp-client.h ./src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp-client.h
    /bin/cp "$SYSTEMD_DIR"/src/systemd/sd-dhcp-lease.h ./src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp-lease.h
    /bin/cp "$SYSTEMD_DIR"/src/systemd/sd-dhcp6-client.h ./src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp6-client.h
    /bin/cp "$SYSTEMD_DIR"/src/systemd/sd-dhcp6-lease.h ./src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp6-lease.h
    /bin/cp "$SYSTEMD_DIR"/src/systemd/sd-event.h ./src/dhcp-manager/systemd-dhcp/src/systemd/sd-event.h
    /bin/cp "$SYSTEMD_DIR"/src/systemd/sd-id128.h ./src/dhcp-manager/systemd-dhcp/src/systemd/sd-id128.h
trivial: fix a comment typo in generate-plugin-docs.pl
Merge branch 'master' into dhcp-merge

Conflicts:
	src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-client.c
	src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-lease.c
	src/dhcp-manager/systemd-dhcp/src/shared/fileio.c
	src/dhcp-manager/systemd-dhcp/src/shared/util.c
	src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp-client.h
	src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp-lease.h
dhcp: re-fix system-dhcp code after re-import
dhcp: update nm-dhcp-systemd code for system-dhcp re-import

Some of the patches we proposed were committed in slightly different
form.
dhcp: update system-dhcp code from upstream
dhcp: fix systemd-dhcp's writing of routes in lease file

inet_ntoa() uses a static buffer, so you can't call it twice in the
same fprintf() call.

https://bugs.freedesktop.org/show_bug.cgi?id=86438
dhcp: fix startup warnings with dhcp=internal

If asked to read a file that doesn't exist, sd_dhcp_lease_load()
returns 0 (success) without setting the out lease argument. So we need
to check both the return status and the lease before proceeding.
dhcp: Simplify nm-dhcp-systemd lease-handling code

An sd_dhcp_lease will always have an associated address, netmask, and
lifetime, so we don't have to check for errors when fetching them.
(The systemd code will fill in a default netmask if the server didn't
provide one; nm-dhcp-systemd's code to do that itself was redundant
and unused.)

Also, log the expiration time and NTP servers, for consistency with
everything else.
man: document the "internal" DHCP client
Merge branch 'dhcp-fixes'