Add functionality to add OCSP stapling info (.ocsp file), issuer (.issuer file) and multi-cert bundles (suffix on pem file based on key type).
This also corrects the order of key, certificate and intermediate in the PEM file, which although HAProxy does not seem to care, was incorrect in the prior version.
HAProxy requires the certificate chain and key to be concatenated and placed somewhere (can be anywhere). This script expects a single environment variable with the path where the concatenated PEM file should be written
