New ctrls to retrieve supported signature algorithms and curves and

extensions to s_client and s_server to print out retrieved valued.

Extend CERT structure to cache supported signature algorithm data.
(backport from HEAD)

apps/s_client.c

@@ -2011,6 +2011,8 @@ static void print_stuff(BIO *bio, SSL *s, int full)
 			BIO_write(bio,"\n",1);
 			}
 
+		ssl_print_sigalgs(bio, s);
+
 		BIO_printf(bio,"---\nSSL handshake has read %ld bytes and written %ld bytes\n",
 			BIO_number_read(SSL_get_rbio(s)),
 			BIO_number_written(SSL_get_wbio(s)));