MessagePartProperties support, direct Brainpool EC TLS support
<ul>
<li>AS4Send did not support to set the message part properties so far, this has been only implemented to the REST API. It is required for the schedule of BDEW messages.</li>
<li>Added TLS support using BrainPool EC certificates, there is a new server parameter now (-enableBrainpoolTLS). This has been realized using a reverse TLS proxy before.</li>
<li>Reworked the certificate renderer for the UI and also the certificate manager display as several keys/certificates used in BDEW have not all issuer/subject values set</li>
<li>Added documentation howto use openssl to get partner certificate chains as this is sometimes compicated because of the EC TLS</li>
<li>The export/import of private keys in the certificate manager to and from pkcs#12 now imports/exports also the certficiates of the trust chain automatically</li>
</ul>