ash,hush: ulimit: add -i RLIMIT_SIGPENDING, -q RLIMIT_MSGQUEUE

ash,hush: ulimit: add -i RLIMIT_SIGPENDING, -q RLIMIT_MSGQUEUE

function                                             old     new   delta
limits_tbl                                           104     120     +16
ulimit_opt_string                                     44      50      +6
limit_chars                                           14      16      +2
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 24/0)               Total: 24 bytes
   text	   data	    bss	    dec	    hex	filename
 981996	    485	   7296	 989777	  f1a51	busybox_old
 982065	    485	   7296	 989846	  f1a96	busybox_unstripped

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