Failover discovered ldap hosts

This hands over all discovered LDAP hosts to the connect method of the LDAPConnection class as a string separated list. The LDAPConnection will handle failover if the host with the highest priority and weight is unresponsive and pick the next one in the list in accordance with novell.com/documentation/developer/jldap/jldapenu/api/com/novell/ldap/LDAPConnection.html#connect(java.lang.String,%20int)

See https://github.com/xwiki-contrib/ldap/pull/26