Shows last ip that was used to login successfully with this useraccount.
Logins from admins using loginAs are ignored

Implementiert Issue #4357
Zeigt die IP-Adresse des letzten erfolgreichen Logins auf dem Dashboard an.
Verändert die gespeicherte IP-Adresse nicht, wenn man sich via "Einloggen als" angemeldet hat.

Needed Database-Changes:

ALTER TABLE `sys_user` ADD `last_login_ip` VARCHAR(50) NULL AFTER `lost_password_reqtime`;
ALTER TABLE `sys_user` ADD `last_login_at` BIGINT(20) NULL AFTER `last_login_ip`;

Tested/Working on Ubuntu 16.04 LTS

Merged language files.

- Fixed mailuser login

This implements ispconfig/ispconfig3#3644

    - make sure umlautdomains can be found in lists.
    - sorting by database name did not work in database quota list.
    - IDN: use standard from 2008 (which also works with "ß").