Synch recent 3.4.2 changes to main trunk

This is merely a synchronization of recent changes for the
Macintosh Carbon port, which were committed to the 3.4.2
branch, to the main trunk.

src/files.c

@@ -130,6 +130,10 @@ static int lockptr;
 #endif
 #endif
 
+#ifdef MAC
+# define unlink macunlink
+#endif
+
 #ifdef USER_SOUNDS
 extern char *sounddir;
 #endif