967566: Enhance the ssl bindings to expose the issuer.

The main reason for this is that when getting a random certificate,
the first question is "where did this come from". Often, the only
way to know this is by looking at the CA. Once this is in, the rct
tool can be enhanced to expose this data.
Merge pull request #76 from candlepin/bkearney/967566

967566: Enhance the ssl bindings to expose the issuer.