getopt32: remove applet_long_options

FEATURE_GETOPT_LONG made dependent on LONG_OPTS.

The folloving options are removed, now LONG_OPTS enables long options
for affected applets:
FEATURE_ENV_LONG_OPTIONS	FEATURE_EXPAND_LONG_OPTIONS
FEATURE_UNEXPAND_LONG_OPTIONS	FEATURE_MKDIR_LONG_OPTIONS
FEATURE_MV_LONG_OPTIONS		FEATURE_RMDIR_LONG_OPTIONS
FEATURE_ADDGROUP_LONG_OPTIONS	FEATURE_ADDUSER_LONG_OPTIONS
FEATURE_HWCLOCK_LONG_OPTIONS	FEATURE_NSENTER_LONG_OPTS
FEATURE_CHCON_LONG_OPTIONS	FEATURE_RUNCON_LONG_OPTIONS

They either had a small number of long options, or their long options are
essential.

Example: upstream addgroup and adduser have ONLY longopts,
we should probably go further and get rid
of non-standard short options.

To this end, make addgroup and adduser "select LONG_OPTS".
We had this breakage caused by us even in our own package!
	#if ENABLE_LONG_OPTS || !ENABLE_ADDGROUP
                /* We try to use --gid, not -g, because "standard" addgroup
                 * has no short option -g, it has only long --gid.
                 */
                argv[1] = (char*)"--gid";
	#else
                /* Breaks if system in fact does NOT use busybox addgroup */
                argv[1] = (char*)"-g";
	#endif

xargs: its lone longopt no longer depends on DESKTOP, only on LONG_OPTS.

hwclock TODO: get rid of incompatible -t, -l aliases to --systz, --localtime

Shorten help texts by omitting long option when short opt alternative exists.

Reduction of size comes from the fact that store of an immediate
(an address of longopts) to a fixed address (global variable)
is a longer insn than pushing that immediate or passing it in a register.
This effect is CPU-agnostic.

function                                             old     new   delta
getopt32                                            1350      22   -1328
vgetopt32                                              -    1318   +1318
getopt32long                                           -      24     +24
tftpd_main                                           562     567      +5
scan_recursive                                       376     380      +4
collect_cpu                                          545     546      +1
date_main                                           1096    1095      -1
hostname_main                                        262     259      -3
uname_main                                           259     255      -4
setpriv_main                                         362     358      -4
rmdir_main                                           191     187      -4
mv_main                                              562     558      -4
ipcalc_main                                          548     544      -4
ifenslave_main                                       641     637      -4
gzip_main                                            192     188      -4
gunzip_main                                           77      73      -4
fsfreeze_main                                         81      77      -4
flock_main                                           318     314      -4
deluser_main                                         337     333      -4
cp_main                                              374     370      -4
chown_main                                           175     171      -4
applet_long_options                                    4       -      -4
xargs_main                                           894     889      -5
wget_main                                           2540    2535      -5
udhcpc_main                                         2767    2762      -5
touch_main                                           436     431      -5
tar_main                                            1014    1009      -5
start_stop_daemon_main                              1033    1028      -5
sed_main                                             682     677      -5
script_main                                         1082    1077      -5
run_parts_main                                       330     325      -5
rtcwake_main                                         459     454      -5
od_main                                             2169    2164      -5
nl_main                                              201     196      -5
modprobe_main                                        773     768      -5
mkdir_main                                           160     155      -5
ls_main                                              568     563      -5
install_main                                         773     768      -5
hwclock_main                                         411     406      -5
getopt_main                                          622     617      -5
fstrim_main                                          256     251      -5
env_main                                             198     193      -5
dumpleases_main                                      635     630      -5
dpkg_main                                           3991    3986      -5
diff_main                                           1355    1350      -5
cryptpw_main                                         233     228      -5
cpio_main                                            593     588      -5
conspy_main                                         1135    1130      -5
chpasswd_main                                        313     308      -5
adduser_main                                         887     882      -5
addgroup_main                                        416     411      -5
ftpgetput_main                                       351     345      -6
get_terminal_width_height                            242     234      -8
expand_main                                          690     680     -10
static.expand_longopts                                18       -     -18
static.unexpand_longopts                              27       -     -27
mkdir_longopts                                        28       -     -28
env_longopts                                          30       -     -30
static.ifenslave_longopts                             34       -     -34
mv_longopts                                           46       -     -46
static.rmdir_longopts                                 48       -     -48
packed_usage                                       31739   31687     -52
------------------------------------------------------------------------------
(add/remove: 2/8 grow/shrink: 3/49 up/down: 1352/-1840)      Total: -488 bytes
   text	   data	    bss	    dec	    hex	filename
 915681	    485	   6880	 923046	  e15a6	busybox_old
 915428	    485	   6876	 922789	  e14a5	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/bbunzip.c b/archival/bbunzip.c
index 9b9fdc8..20ab893 100644
--- a/archival/bbunzip.c
+++ b/archival/bbunzip.c
@@ -389,9 +389,10 @@
 int gunzip_main(int argc UNUSED_PARAM, char **argv)
 {
 #if ENABLE_FEATURE_GUNZIP_LONG_OPTIONS
-	applet_long_options = gunzip_longopts;
-#endif
+	getopt32long(argv, "cfkvqdtn", gunzip_longopts);
+#else
 	getopt32(argv, "cfkvqdtn");
+#endif
 	argv += optind;
 
 	/* If called as zcat...
diff --git a/archival/cpio.c b/archival/cpio.c
index 38bab82..f2165be 100644
--- a/archival/cpio.c
+++ b/archival/cpio.c
@@ -360,9 +360,8 @@
 	char *cpio_owner;
 	IF_FEATURE_CPIO_O(const char *cpio_fmt = "";)
 	unsigned opt;
-
 #if ENABLE_LONG_OPTS
-	applet_long_options =
+	const char *long_opts =
 		"extract\0"      No_argument       "i"
 		"list\0"         No_argument       "t"
 #if ENABLE_FEATURE_CPIO_O
@@ -390,9 +389,9 @@
 	/* -L makes sense only with -o or -p */
 
 #if !ENABLE_FEATURE_CPIO_O
-	opt = getopt32(argv, OPTION_STR, &cpio_filename, &cpio_owner);
+	opt = getopt32long(argv, OPTION_STR, long_opts, &cpio_filename, &cpio_owner);
 #else
-	opt = getopt32(argv, OPTION_STR "oH:" IF_FEATURE_CPIO_P("p"),
+	opt = getopt32long(argv, OPTION_STR "oH:" IF_FEATURE_CPIO_P("p"), long_opts,
 		       &cpio_filename, &cpio_owner, &cpio_fmt);
 #endif
 	argv += optind;
diff --git a/archival/dpkg.c b/archival/dpkg.c
index 90ad876..852e0ca 100644
--- a/archival/dpkg.c
+++ b/archival/dpkg.c
@@ -1766,8 +1766,7 @@
 
 	INIT_G();
 
-	IF_LONG_OPTS(applet_long_options = dpkg_longopts);
-	opt = getopt32(argv, "CilPruF:", &str_f);
+	opt = getopt32long(argv, "CilPruF:", dpkg_longopts, &str_f);
 	argv += optind;
 	//if (opt & OPT_configure) ... // -C
 	if (opt & OPT_force) { // -F (--force in official dpkg)
diff --git a/archival/gzip.c b/archival/gzip.c
index 4cf34ac..9c53895 100644
--- a/archival/gzip.c
+++ b/archival/gzip.c
@@ -2216,11 +2216,12 @@
 	SET_PTR_TO_GLOBALS((char *)xzalloc(sizeof(struct globals)+sizeof(struct globals2))
 			+ sizeof(struct globals));
 
-#if ENABLE_FEATURE_GZIP_LONG_OPTIONS
-	applet_long_options = gzip_longopts;
-#endif
 	/* Must match bbunzip's constants OPT_STDOUT, OPT_FORCE! */
+#if ENABLE_FEATURE_GZIP_LONG_OPTIONS
+	opt = getopt32long(argv, "cfkv" IF_FEATURE_GZIP_DECOMPRESS("dt") "qn123456789", gzip_longopts);
+#else
 	opt = getopt32(argv, "cfkv" IF_FEATURE_GZIP_DECOMPRESS("dt") "qn123456789");
+#endif
 #if ENABLE_FEATURE_GZIP_DECOMPRESS /* gunzip_main may not be visible... */
 	if (opt & 0x30) // -d and/or -t
 		return gunzip_main(argc, argv);
diff --git a/archival/tar.c b/archival/tar.c
index f62b330..44ab246 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -940,6 +940,11 @@
 	"exclude\0"             Required_argument "\xff"
 # endif
 	;
+# define GETOPT32 getopt32long
+# define LONGOPTS ,tar_longopts
+#else
+# define GETOPT32 getopt32
+# define LONGOPTS
 #endif
 
 int tar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -980,9 +985,6 @@
 		":\xf9+" // --strip-components=NUM
 #endif
 	;
-#if ENABLE_FEATURE_TAR_LONG_OPTIONS
-	applet_long_options = tar_longopts;
-#endif
 #if ENABLE_DESKTOP
 	/* Lie to buildroot when it starts asking stupid questions. */
 	if (argv[1] && strcmp(argv[1], "--version") == 0) {
@@ -1019,7 +1021,7 @@
 		}
 	}
 #endif
-	opt = getopt32(argv,
+	opt = GETOPT32(argv,
 		"txC:f:Oopvk"
 		IF_FEATURE_TAR_CREATE(   "ch"    )
 		IF_FEATURE_SEAMLESS_BZ2( "j"     )
@@ -1030,6 +1032,7 @@
 		IF_FEATURE_SEAMLESS_Z(   "Z"     )
 		IF_FEATURE_TAR_NOPRESERVE_TIME("m")
 		IF_FEATURE_TAR_LONG_OPTIONS("\xf9:") // --strip-components
+		LONGOPTS
 		, &base_dir // -C dir
 		, &tar_filename // -f filename
 		IF_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T