Fixed regex in prefix validation under System > interface config that prevented numbers in prefixes.

Completly same functionality as VHost-Subdomain, not to disable if already existing vhostalias-somains in system.

Fixed login as

Reverted SVN trunk back to revision 3938 to remove changes in default theme an a replacement of the ispconfig logo.

- Added backup size to web backups

  New global option to grant reseller users access to the options (advanced) tab in web domains and vhost subdomains

Implemented checkboxes in Interface Config to enable showing/hiding the tabs Mail Filters, Autoresponders and Custom Rules for mailboxes.

See also http://www.howtoforge.com/forums/showthread.php?t=59539

- need to have the pecl idn and intl modules installed
  or
- have the idna_convert class in the classes/idn/ path

Implemented:  FS#2388 - Optional confirm window on changing tabs

http://bugtracker.ispconfig.org/index.php?do=details&task_id=1689

Using these variables in welcome email from admin, when mailbox is created.