Fixed: PHP notices in jailkit user plugin.

- Fixed bug in updater that made ispconfig invoices directory unreadable.
- Removed passing of variables by reference in ispconfig monitor.
- Changed monitor of opensuse updates so that the command does not install them automatically.

- Added a timezone setting in config.inc.ohp file

- Fixed a problem with german umlauts in monitor.
- Added code to update.php and autoupdate.php that checks the mysql root password before the update starts.
- Fixed: FS#1848 - changing password of ssh user >>> rights in webXX are changed

No commit message

- Installer adds Apache and nginx user to ispapps group.
- Installer makes sure that /var/www/apps has 755 permissions.

- Added empty function configure_fail2ban() to get rid of the following fatal error during installation on non-Debian/Ubuntu systems: PHP Fatal error:  Call to undefined method installer::configure_fail2ban() in /tmp/trunk/install/install.php on line 266

- Fixed "PHP Notice:  Undefined property: installer::$ispconfig_interface_installed in /tmp/trunk/install/update.php on line 337" when updating an ISPConfig server with nginx.

- Enabled Security Level (Server Config > Web > Security Level) for nginx.

fix #1747 - check for amavised for postfix rules -> pure webserver need for php sendmail, most often postfix is used for it, because admin know it. I checked different repos for differnet names, alwas amavsid or with -new.