Support for PEM-formatted TLS host keys and certificates

When configuring a Server document or Web Site document with a path to a keyring file, administrators can now specify text files containing PEM-formatted keys and certificates instead of ".kyr" files in the proprietary format.

These PEM-formatted files must have names that end in a ".pem" extension. In addition, they must contain a PEM-formatted RSA or ECDSA private key and the set of PEM-formatted certificates forming the certificate chain for that private key, ordered with the leaf certificate first. This is the same format as that used by the kyrtool import all command.

This feature is intended as a test bed for future work supporting PEM-formatted keys and certificates. It may not be exposed in the final GA release of Domino 12, depending on the Early Access feedback we receive.