scsi_id: cleanup

Remove -i option which would case exit(1) to happen.
Remove some unused code.
Convert to bool where appropriate.
Simplify things a bit.
Always free everything.

https://bugzilla.redhat.com/show_bug.cgi?id=1043304
udevadm,scsi_id: add short options to help strings and to the man page

Also clean things up a bit here and there.
udevadm: modernization
machinectl: show_properties() already logs the error
man: fix grammar issues in journalctl(1)

And add a missing <option> tag around "--setup-keys" under "--force".
man: be more explicit about option arguments that take 128-bit IDs in journalctl(1)

It may not be immediately obvious to the reader what "ID128" is, so replace the
example option argument "ID128" with "128-bit-ID".
man: add DOI for refereed article on Forward Secure Sealing to journald.conf(5)

In journalctl(1), be more explicit about the reference to "Seal=" in
journald.conf(5) and what information can be found there.
journalctl,zsh-completion: fix several issues in --help message text

-- fix grammar and reword some descriptions for clarity
-- add a useful description of what --follow does
-- fix the description for --after-cursor
-- properly introduce the FSS acronym for "Forward Secure Sealing" in
both sections
-- clarify the --disk-usage command

[zj: perform similar changes to zsh completions]

squash! journalctl: fix several issues in --help message text
loginctl: replace strv_append() by strv_extend()
loginctl: use show_properties() to get login1 properties

Commit f8f14b3654bcd introduced a regression that makes loginctl ignore
the "--property" option.

This patch fixes the bug, it uses a new show_properties() function to
query and filter properties.
loginctl: improve print_{session|user|seat}_status_info() functions

1) Instead of checking if we need to print a new line on each iteration,
pass the "new_line" as a pointer to those functions, so they can use
it to check if a new line is needed. This makes the code more consistent
as it is done in other places: machinectl, systemctl...

2) Move the error messages from show_{session|user|seat}() to their
appropriate print_{session|user|seat}_status_info() functions, this will
prevent from logging an error message twice in case show_properties()
fails and it will improve code readability.

3) Also do not ignore error codes on these functions.
systemct: add empty line between units in cat