- Similar subcommands for 'uuids' as there is for 'ids' ('_uuids' and '_zshuuids').
- Extends the scope and the precision of the unit tests for ids.
- Corresponding documentation in the man pages.
- Obsoleted Command::exectute 'commandLine' argument. It is worse
than unnecessary, it is an uncategorized raw argument string, which
is only really useful for the 'execute' command, which itself now
calls Arguments::combine to reconstruct the command line string.