timesyncd: the IP_TOS sockopt is really just an optimization, we shouldn't fail if we can't set it

This partially undos 2f905e821e0342c36f5a5d3a51d53aabccc800bd
calendar: make freeing a calendar spec object deal fine with NULL

In order to make object destruction easier (in particular in combination
with _cleanup_) we usually make destructors deal with NULL objects as
NOPs. Change the calendar spec destructor to follow the same scheme.
delta: use wait_for_terminate_and_warn() to generate warnin when diff fails
NEWS: more preparations for 217
update TODO
time: also support 'infinity' syntax in parse_nsec()

Let's make parse_usec() and parse_nsec() work similar
time: earlier exit from format_timestamp_relative() on special times
time: minor simplification
time: don't do comparison twice
sd-bus: if we don't manage to properly allocate the error message for an sd_bus_error, just go on

sd_bus_error_setfv() must initialize the sd_bus_error value to some
sensible value and then return a good errno code matching that. If it
cannot work at all it should set the error statically to the OOM error.
But if it can work half-way (i.e. initialize the name, but not the
message) it should do so and still return the correct errno number for
it.

This effectively reverts 8bf13eb1e02b9977ae1cd331ae5dc7305a305a09
bus-proxy: it's OK if getpeercred doesn't work

We should use the data if we can (if stdin/stdout is an AF_UNIX socket),
but still work if we can't (if stdin/stdout are pipes, like in the SSH
case).

This effectively reverts 55534fb5e4742b0db9ae5e1e0202c53804147697
journalctl: correct help text for --until

http://bugs.debian.org/766598
calendarspec: fix typo in "annually"

https://bugs.freedesktop.org/show_bug.cgi?id=85447
Rearrange Unit to make pahole happy

After all we have lots of those.
systemctl: do not ignore errors in symlink removal

On an ro fs, systemctl disable ... would fail silently.
journald: fix flushing

Commit 74055aa762 'journalctl: add new --flush command and make use of
it in systemd-journal-flush.service' broke flushing because journald
checks for the /run/systemd/journal/flushed file before opening the
permanent journal. When the creation of this file was postponed,
flushing stoppage ensued.
Merge remote-tracking branch 'upstream/master'