Use apps_shutdown() in all applications, in case someone decides not

to go the monolith way (does anyone do that these days?).

NOTE: a few applications are missing in this commit.  I've a few more
changes in them that I haven't tested yet.

apps/engine.c

@@ -486,5 +486,6 @@ end:
 	sk_pop_free(pre_cmds, identity);
 	sk_pop_free(post_cmds, identity);
 	if (bio_out != NULL) BIO_free_all(bio_out);
+	apps_shutdown();
 	EXIT(ret);
 	}