Merge branch 'ldap-auth' into 'master'

Add support for LDAP manager and search

New configuration settings have been implemented to allow additional
LDAP environments:
* `security.ldap.user-search-filter`
* `security.ldap.user-search-base`
* `security.ldap.manager-user-dn`
* `security.ldap.manager-password`

See merge request !12