First batch of changes from FailSafeC

This is all tiny stuff - allow overriding WIDENED_PROTOTYPES from the hints
file, missing NO_SIGNAL conditionals, remove a GCC-ism, conditional indentation,
void return in a non-void function.

sys/unix/unixmain.c

@@ -183,7 +183,9 @@ char *argv[];
 	 */
 	u.uhp = 1;	/* prevent RIP on early quits */
 	program_state.preserve_locks = 1;
+#ifndef NO_SIGNAL
 	sethanguphandler((SIG_RET_TYPE)hangup);
+#endif
 
 	process_options(argc, argv);	/* command line options */
 	init_nhwindows(&argc, argv);	/* now we can set up window system */
@@ -268,7 +270,9 @@ char *argv[];
 		const char *fq_save = fqname(SAVEF, SAVEPREFIX, 1);
 
 		(void) chmod(fq_save,0);	/* disallow parallel restores */
+#ifndef NO_SIGNAL
 		(void) signal(SIGINT, (SIG_RET_TYPE) done1);
+#endif
 #ifdef NEWS
 		if(iflags.news) {
 		    display_file(NEWS, FALSE);

sys/unix/unixunix.c

@@ -298,8 +298,10 @@ int wt;
 		return(0);
 	}
 	/* fork succeeded; wait for child to exit */
+#ifndef NO_SIGNAL
 	(void) signal(SIGINT,SIG_IGN);
 	(void) signal(SIGQUIT,SIG_IGN);
+#endif
 	(void) wait( (int *) 0);
 #ifdef _M_UNIX
 	sco_mapoff();
@@ -307,9 +309,11 @@ int wt;
 #ifdef __linux__
 	linux_mapoff();
 #endif
+#ifndef NO_SIGNAL
 	(void) signal(SIGINT, (SIG_RET_TYPE) done1);
-#ifdef WIZARD
+# ifdef WIZARD
 	if(wizard) (void) signal(SIGQUIT,SIG_DFL);
+# endif
 #endif
 	if(wt) {
 		raw_print("");