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/runit/svlogd.c b/runit/svlogd.c
index 9c169da..73570da 100644
--- a/runit/svlogd.c
+++ b/runit/svlogd.c
@@ -222,9 +222,11 @@
 		int fd;
 
 		/* child */
-		signal(SIGTERM, SIG_DFL);
-		signal(SIGALRM, SIG_DFL);
-		signal(SIGHUP, SIG_DFL);
+		bb_signals(0
+			+ (1 << SIGTERM)
+			+ (1 << SIGALRM)
+			+ (1 << SIGHUP)
+			, SIG_DFL);
 		sig_unblock(SIGTERM);
 		sig_unblock(SIGALRM);
 		sig_unblock(SIGHUP);
@@ -903,10 +905,10 @@
 	sigaddset(&blocked_sigset, SIGALRM);
 	sigaddset(&blocked_sigset, SIGHUP);
 	sigprocmask(SIG_BLOCK, &blocked_sigset, NULL);
-	sig_catch(SIGTERM, sig_term_handler);
-	sig_catch(SIGCHLD, sig_child_handler);
-	sig_catch(SIGALRM, sig_alarm_handler);
-	sig_catch(SIGHUP, sig_hangup_handler);
+	bb_signals_recursive(1 << SIGTERM, sig_term_handler);
+	bb_signals_recursive(1 << SIGCHLD, sig_child_handler);
+	bb_signals_recursive(1 << SIGALRM, sig_alarm_handler);
+	bb_signals_recursive(1 << SIGHUP, sig_hangup_handler);
 
 	logdirs_reopen();