Create release note for migration from 1.2.3 to 1.3

Hello,

we need to create a full release note from 1.2.3 to 1.3.

before putting that into the official notes, everthing can be condensed into this ticket

For migrating from 1.2.3 core to 1.3 I only did the following commands

# changing repo (installing apt-transport-https if not already installed)
apt-get update
apt-get install fusiondirectory fusiondirectory-schema
# update the schemas
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/core-fd-conf.schema

added 5m of time spent at 2019-01-09

With all the plugins we need to modify the next schemas

fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/core-fd-conf.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/supann-fd-conf.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/audit-fd.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/ejbca-fd.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/systems-fd-conf.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/systems-fd.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/argonaut-fd.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/user-reminder-fd-conf.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/community-fd.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/dhcp-fd.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/weblink-fd.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/postfix-fd.schema
fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/opsi-fd.schema

added 1h 20m of time spent at 2019-01-14

added user-manual label

changed milestone to %FusionDirectory 1.3

moved from fd#5941 (closed)

mentioned in commit 00598570

reopened

mentioned in commit c9fbe440

closed via commit 471c427e

mentioned in commit 7e59d3ae

added release notes label