Add options to write lightweight CA cert or chain to file
Administrators need a way to retrieve the certificate or certificate
chain of an IPA-managed lightweight CA. Add params to the `ca'
object for carrying the CA certificate and chain (as multiple DER
values). Add the `--chain' flag for including the chain in the
result (chain is also included with `--all'). Add the
`--certificate-out' option for writing the certificate to a file (or
the chain, if `--chain' was given).
Fixes: https://fedorahosted.org/freeipa/ticket/6178
Reviewed-By: Jan Cholasta <jcholast@redhat.com>
Reviewed-By: Tomas Krizek <tkrizek@redhat.com>