unshare: new applet

unshare: new applet

function                                             old     new   delta
unshare_main                                           -     873    +873
.rodata                                           154444  155131    +687
packed_usage                                       30329   30520    +191
unshare_longopts                                       -     106    +106
mount_namespaces                                       -      99     +99
mount_or_die                                           -      51     +51
ns_list                                                -      48     +48
wait_for_exitstatus                                    -      41     +41
opt_str                                                -      17     +17
applet_names                                        2510    2518      +8
applet_main                                         2912    2920      +8
applet_suid                                           91      92      +1
applet_install_loc                                   182     183      +1
------------------------------------------------------------------------------
(add/remove: 8/0 grow/shrink: 6/0 up/down: 2131/0)           Total: 2131 bytes
   text	   data	    bss	    dec	    hex	filename
 826110	   4070	   9080	 839260	  cce5c	busybox_old
 827961	   4078	   9080	 841119	  cd59f	busybox_unstripped

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>