openssl: skip trace outputs for ssl_ver == 0

The OpenSSL trace callback is wonderfully undocumented but given a
journey in the source code, it seems the cases were ssl_ver is zero
doesn't follow the same pattern and thus turned out confusing and
misleading. For now, we skip doing any CURLINFO_TEXT logging on those
but keep sending them as CURLINFO_SSL_DATA_OUT/IN.

Also, I added direction to the text info and I edited some functions
slightly.

Bug: https://github.com/bagder/curl/issues/219
Reported-by: Jay Satiro, Ashish Shukla