fail2ban compatible login log (no permissions for /var/log/ispconfig/login.log) - to be fixed! (FS#2244)

- Fixed: FS#2292 - monitor_tools.inc.php uses /var/vmail and not the mail directory specified in server config
- Changed code comment in login/index.php file.

added tmp_vars for login + password_reset as replacement for hardcoded language non-neutral expressions

Fixed: Notice: Undefined variable: maintenance_mode_error in /usr/local/ispconfig/interface/web/login/index.php on line 238

reason: not necessary here, check is in line 141, when checking in line 117 and setting $user to false user blocked message will never show

as ones affecting theme can take place now.
Affected files: interface/web/login/logout.php

Added destructor and session write to app class instead.

- Added UFW firewall support.