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/dgst.c

diff --git a/apps/dgst.c b/apps/dgst.c
index 1fbef6b..e3edf30 100644
--- a/apps/dgst.c
+++ b/apps/dgst.c
@@ -347,6 +347,7 @@
 	EVP_PKEY_free(sigkey);
 	if(sigbuf) OPENSSL_free(sigbuf);
 	if (bmd != NULL) BIO_free(bmd);
+	apps_shutdown();
 	EXIT(err);
 	}