[Web] Add system mails (send mails to all mailboxes via LMTP)
[Web] Allow to add more administrators
[Web] Fix domain administrator editing
[Web] Remove some foreign keys
[Web] Remove username from API
[Web] Remove more .php extension from code
[Web] More minor fixes
[Web] Allow to edit alias address
[Web] $_SESSION['return'] now contains arrays and allows multiple returned messages and log entries
[Web] Some language string changes
[Web] General SQL exception handler, remove all try catch handlers
[Web] Alias table now has an ID as primary key
[Web] Be more aggressive with localStorage cleaning
[Web] Add mailcow UI logs
[Web] Changes to _SESSION['return'] logic and logger (more to come)
[Web] Show last login
[Web, Postfix] Allow to disable sender check completely
[Web] Many minor fixes
[Web] Update some libs
