Show metadata and correct protocolname in mail

templates/protocol-mail.txt

-Protocol der {{protocol.name}} vom {{protocol.date|datify}}
+Protokoll der {{protocol.protocoltype.name}} vom {{protocol.date|datify}}
 
 Datum: {{protocol.date|datify_long}}
 {% if protocol.start_time is not none and protocol.end_time is not none %}
 Zeit: von {{protocol.start_time|timify}} bis {{protocol.end_time|timify}}
 {% endif %}
-Protokoll: {{protocol.author}}
-Anwesende: {{protocol.participants}}
+{% for meta in protocol.meta %}
+{{meta.name}}: meta.value
+{% endfor %}
 
 Die Tagesordnung ist:
 {% if not protocol.has_nonplanned_tops() %}