Added missing strings in some templates to english transalations

Fixed: FS#1313 - Email > Global Filters > Postfix Whitelist > Add new Whitelist record: "Witelist Address" typo 

Enhancement of the Email-Domain-List. The user can only select the server as filter, he has some mail-domains at (and not ALL Servers of the server-farm)

1) Edit a domain: The selected domain is also selected in the dropdown-list
2) Edit a domain: The admin can now select any domain not only his/her

Fixed a bug: if the domain-module is used and there are NO domains in the list, then the user was able to free edit the domain-name. This bug is fixed now and a empty list is generated, so the user can enter only a empty name!

Added a new module called "domain". With this module you can manage all domains (web + mail). Per default this module is not active. To activate it, you have to change the System Interface Config -> domains -> use the domain module. You also have to activate the domain-module for the admin (and for every client if you want). Important: you can not use this module if you have reseller!

- Set a fixed column width for the buttons in the client and reseller list.

Added European Portuguese translation. Many thanks to Miguel Almeida to provide this language file set.