Contributed by Maarten Vanraes (AL13N)

Fix things so that chains of certificates work in the server and client
certificate files.

This only really works for OpenSSL-based builds, as yassl is unable to read
multiple certificates from a file.  The patch below to yassl/src/ssl.cpp
doesn't fix that, but just arranges that the viosslfactories.c patch won't
have any ill effects in a yassl build.