libbb: introduce bb_signals and bb_signals_recursive,
which sets same handler for many signals. sig_catch is nuked
(bb_signals_recursive is more descriptive name).
*: use them as appropriate. 

function                                             old     new   delta
bb_signals_recursive                                   -      95     +95
bb_signals                                             -      52     +52
run_command                                          258     273     +15
svlogd_main                                         1368    1377      +9
runsv_main                                          1746    1752      +6
runsvdir_main                                       1643    1646      +3
UNSPEC_print                                          64      66      +2
time_main                                           1128    1127      -1
...
resize_main                                          246     210     -36
sig_catch                                             63       -     -63
set_fatal_sighandler                                  85      14     -71
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 5/24 up/down: 182/-548)        Total: -366 bytes


diff --git a/procps/top.c b/procps/top.c
index a47150e..f4bb509 100644
--- a/procps/top.c
+++ b/procps/top.c
@@ -772,8 +772,10 @@
 	/* unbuffered input, turn off echo */
 	new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
 
-	signal(SIGTERM, sig_catcher);
-	signal(SIGINT, sig_catcher);
+	bb_signals(0
+		+ (1 << SIGTERM)
+		+ (1 << SIGINT)
+		, sig_catcher);
 	tcsetattr(0, TCSANOW, (void *) &new_settings);
 	atexit(reset_term);
 #endif /* FEATURE_USE_TERMIOS */