Shorten internal subcommand

Will make code less ugly at places.

src/complete.bash

             ;;
         *)
             COMPREPLY=(
-                $(compgen -W "$(satcmd _ls_subcommands)" ${cur})
+                $(compgen -W "$(satcmd _ls_sc)" ${cur})
             )
     esac
 }

src/shellfu/saturnin.sh

     debug -v SHELLFU_PATH SATURNIN_LIBEXEC SATURNIN_CONF_PATH
     case "$subcommand" in
         conf)               saturnin__conf "$@" ;;
-        _ls_subcommands)    saturnin__lssc ;;
+        _ls_sc)    saturnin__lssc ;;
         _lsfun)             shellfu-get lsfun ;;
         _lsmod)             shellfu-get lsmod ;;
         *)                  saturnin__runsc "$subcommand" "$@" ;;