fix null pointer dereference in ocsp verification code in case no certificate
is sent as part as the ocsp reply.

Addresses BIT-1212

There is an additional issue here that prevents the correct verification of
proofs in quite a few cases; this will be addressed in a separate commit.
Fix ocsp reply validation - there were a few things that definitely were wrong.

Now the right signer certificate for the reply is looked up (and no longer assumed that it is the first one) and a few compares are fixed. Plus - there are more test cases that partially send certificates in the ocsp message and partially do not - and it seems to work fine in all cases.

Addresses BIT-1212
Also make links in documentation templates protocol relative.

In case we do a point release, including this commit would be very
helpful - without the bro documentation pages are somewhat broken
over https.
Merge remote-tracking branch 'origin/fastpath'

* origin/fastpath:
  Also make links in documentation templates protocol relative.
Merge remote-tracking branch 'origin/topic/johanna/ticket-1212'

* origin/topic/johanna/ticket-1212:
  Fix ocsp reply validation - there were a few things that definitely were wrong.
  fix null pointer dereference in ocsp verification code in case no certificate is sent as part as the ocsp reply.