Add calls to bindtextdomain() and textdomain()

Currently there are two domains, one for the sudo front-end and
one for the sudoers plugin and its associated utilities.

plugins/sudoers/iolog.c

@@ -433,6 +433,10 @@ sudoers_io_open(unsigned int version, sudo_conv_t conversation,
 	goto done;
     }
 
+#ifdef HAVE_LIBINTL_H
+    bindtextdomain("sudoers", LOCALEDIR);
+#endif
+
     sudo_setpwent();
     sudo_setgrent();