Some of the options in systemd can take multiple arguments, such as
systemctl's --type option. Previously, you would only be able to
complete a single type after the -t, but now zsh will continue to
complete the types, separating them by commas.
systemd-inhibit's --what command has colon (:), and that has been taken
into account.
_hosts_or_user_at_host was used by 6 different completions, and
previously was in all 6 of those files. I moved it out to its own file,
_sd_hosts_or_user_at_host. This will be autoloaded for use in other
completion functions. It also allows external completions to use this
function by simply calling _sd_hosts_or_user_at_host as in the systemd
completions.
Splitting things unnecessarily at newlines causes tab completion to take
an extremely long time. Also add a note saying that caching is not good
for journalctl's completion.
Moved zsh shell completion to shell-completion/zsh/_systemd for
automake's sake. Also allow users to specify where the files should go
with::
./configure --with-zshcompletiondir=/path/to/some/where
and by default going to `$datadir/zsh/site-functions`