ls: implement -Q and -g (-g was accepted but ignored)

function                                             old     new   delta
print_name                                             -     198    +198
showfiles                                           1489    1508     +19
ls_options                                            30      31      +1
opt_flags                                            112     108      -4
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/1 up/down: 218/-4)            Total: 214 bytes

1 file changed