Improve certificate and alias handling in openxpkiadm
Improve certificate and alias handling in openxpkiadm

Support import of DER encoded certificate files
Allow --file instead if --identifier for alias update
Allow --key with alias --update
Add force-flags ignore/update to alias create command

Those changes should ease alias/certificate import from automated scripts
where existing data should be ignored or updated.

openxpki/openxpki,openxpki/openxpki,openxpki/openxpki,openxpki/openxpki