ls: replace -e with --full-time, add --group-directories-first, delete -K

ls: replace -e with --full-time, add --group-directories-first, delete -K

-K and -e were non-standard

function                                             old     new   delta
static.ls_longopts                                     9      47     +38
ls_main                                              748     776     +28
display_single                                       901     928     +27
sortcmp                                              254     258      +4
ls_options                                            32      31      -1
opt_flags                                            100      96      -4
packed_usage                                       31032   30977     -55
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/3 up/down: 97/-60)             Total: 37 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>