Client-side OCSP stapling support.

Remove the old implementation which was excessively general. This mirrors the
SCT support and adds a single boolean flag to request an OCSP response with no
responder IDs, extensions, or frills. The response, if received, is stored on
the SSL_SESSION so that it is available for (re)validation on session
resumption; Chromium revalidates the saved auth parameters on resume.

Server support is unimplemented for now. This API will also need to be adjusted
in the future if we implement RFC 6961.

Change-Id: I533c029b7f7ea622d814d05f934fdace2da85cb1
Reviewed-on: https://boringssl-review.googlesource.com/1671
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/include/openssl/ssl3.h b/include/openssl/ssl3.h
index 2e9b8cc..44f9367 100644
--- a/include/openssl/ssl3.h
+++ b/include/openssl/ssl3.h
@@ -469,6 +469,11 @@
 		/* Server-only: cert_request is true if a client certificate was
 		 * requested. */
 		int cert_request;
+
+		/* certificate_status_expected is true if OCSP stapling was
+		 * negotiated and the server is expected to send a
+		 * CertificateStatus message. */
+		char certificate_status_expected;
 		} tmp;
 
         /* Connection binding to prevent renegotiation attacks */