This adds support for naming file descriptors passed using socket
activation. The names are passed in a new $LISTEN_FDNAMES= environment
variable, that matches the existign $LISTEN_FDS= one and contains a
colon-separated list of names.
This also adds support for naming fds submitted to the per-service fd
store using FDNAME= in the sd_notify() message.
This also adds a new FileDescriptorName= setting for socket unit files
to set the name for fds created by socket units.
This also adds a new call sd_listen_fds_with_names(), that is similar to
sd_listen_fds(), but also returns the names of the fds.
systemd-activate gained the new --fdname= switch to specify a name for
testing socket activation.
This is based on #1247 by Maciej Wereski.
Fixes#1247.
This modifies the strv in-place, replacing strings with their escaped
version. It's mostly just a convenience function for when you need to
join a strv together because it's passed as a string to something, and
the separator needs escaping.
strv_split_extract is to strv_split_quotes as extract_first_word was to
unquote_first_word.
Now there's extract_first_word for extracting a single argument,
extract_many_words for extracting a bounded number of arguments,
and strv_split_extract for extracting an arbitrary number of arguments.
