0.9.8e Compatibility (CentOS/RHEL 5)

This PR adds 0.9.8e compatibility so we can install on CentOS/RHEL 5 boxes that have an updated Python but default system OpenSSL (which is unfortunately very common).

I've temporarily added CentOS 5 to the PR builder as well, but will permanently add it to the build matrix for jenkins (both PR and master job) when this lands.