use safe -i: streamline s() and g() for robustness (re: 7ea1fb16)
use safe -i: streamline s() and g() for robustness (re: 7ea1fb16)

lib/modernish/mdl/safe.mm: s(), g():
- Streamline processing of long options. Translate long options to
  short option equivalents if they exist, instead of duplicating
  the functionality for both.
- Remove broken use of traps to restore settings on interrupt.
  Instead, use the only safe method: subshells. This may have
  slightly worse performance but it's fine for interactive.
- Separate code to show split/glob state into their own functions.
- Remove dependency on var/stack/trap.
- Add dependency on var/shellquote.

modernish/modernish