Add systemd-timesync user for systemd-timesyncd in postinst.
Move transitional libraries to oldlibs/extra
TODO: doesn't seem to work, still get "trying to overwrite..." error

Add Breaks/Replaces on libsystemd-daemon-dev to libsystemd-dev

sd-daemon.h moved from libsystemd-daemon-dev to libsystemd-dev,
add appropriate Breaks/Replaces.