Feature request - Support multiple different LDAPs / ADs as authentication source

[RolandFelnhofer]

It would be a significant improvement if multiple different LDAP-Directories and/or Active Directories would be supported! Currently only multiple LDAP-Server for ONE LDAP-Directory are support. Maybe this functionality could be used to connect and support multiple DIFFERENT LDAP-Directories. Using trusts for AD would be an option as well but would be limited (?) to Active Directory only and therefore less scalable and flexible.