logind: allow switching to unused VTs via SwitchTo()

If compositors use the new SwitchTo() logic to map F1-F12, we should allow
them to switch to unregistered VTs, too. Otherwise, the auto-spawn logic
of gettys won't trigger.

Reported-by: Jasper St. Pierre <jstpierre@mecheye.net>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
systemctl: fix visual alignment for lines prefixed with color dots
load-fragment: ConditionFirstBoot wants a bool string, not a path
accelerometer: Don't wait for new data from the sensor

Instead of waiting for new data from the sensor, which might be
a long time coming, depending on the sensor device, ask the kernel
for the last state for that particular input device.
escape: move to rootbindir

The systemd-escape utility might be used during early boot (e.g. when
being triggered from udev rules), so move it to rootbindir to support
systems with a split /usr setup.
update .gitignore
fix #ifdef
journal/compress: improve xz compression performance

The new lzma2 compression options at the top of compress_blob_xz are
equivalent to using preset "0", exept for using a 1 MiB dictionary
(the same as preset "1"). This makes the memory usage at most 7.5 MiB
in the compressor, and 1 MiB in the decompressor, instead of the
previous 92 MiB in the compressor and 8 MiB in the decompressor.

According to test-compress-benchmark this commit makes XZ compression
20 times faster, with no increase in compressed data size.
Using more realistic test data (an ELF binary rather than repeating
ASCII letters 'a' through 'z' in order) it only provides a factor 10
speedup, and at a cost if a 10% increase in compressed data size.
But that is still a worthwhile trade-off.

According to test-compress-benchmark XZ compression is still 25 times
slower than LZ4, but the compressed data is one eighth the size.
Using more realistic test data XZ compression is only 18 times slower
than LZ4, and the compressed data is only one quarter the size.

$ ./test-compress-benchmark
XZ: compressed & decompressed 2535300963 bytes in 42.30s (57.15MiB/s), mean compresion 99.95%, skipped 3570 bytes
LZ4: compressed & decompressed 2535303543 bytes in 1.60s (1510.60MiB/s), mean compresion 99.60%, skipped 990 bytes
hostnamed: add a new chassis type for watches
hostnamed: update documentation with new "watch" chassis type
timedated: manage systemd-timesyncd directly instead of lists of alternatives

Alternative NTP implementations should add a:
  Conflicts=systemd-timesyncd.service
to take over the built-in NTP functionality of systemd.
units: make ExecStopPost action part of ExecStart

Currently after exiting rescue shell we isolate default target. User
might want to isolate to some other target than default one. However
issuing systemctl isolate command to desired target would bring system
to default target as a consequence of running ExecStopPost action.

Having common ancestor for rescue shell and possible followup systemctl
default command should fix this. If user exits rescue shell we will
proceed with isolating default target, otherwise, on manual isolate,
parent shell process is terminated and we don't isolate default target,
but target chosen by user.

Suggested-by: Michal Schmidt <mschmidt@redhat.com>
update TODO
sysusers: don't allow user names longer than UT_NAMESIZE

As pointed out by Miloslav Trmač it might be a good idea to make sure
that usernames stay with in the utmp-defined limits.
sysusers: don't allow control characters in gecos fields
update TODO
event: pull in sd-event.h from event-util.h
resolved: properly free network monitor
nss-myhostname: various modernizations
nss-myhostname: following the usual naming scheme for .c/.h files