Fixed a bug in Opensuse installer (permissions of squirrelmail files)
Fixed a issue in smtp-authentication on courier-imap systems when custom usernames are used.

- Added function to detect the apache version to installer.
- Added support for apache 2.4 to vhots templates for ispconfig vhost and apps vhost in installer.

Fixed: FS#3032 - dovecot: master: Warning: /var/www/clients/client20/web36/log is no longer mounted. If this is inten

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

Fixed: FS#2378 - $conf['theme'] value in interface/lib/config.inc.php is overwritten (reset to 'default') on update

Implemented: FS#2283 - Add O option to dovecot transport in postfix master.cf so that X-Original-To: header is added.

Merged revisions 3049-3051,3053-3054,3058,3070,3074-3077,3082,3086-3088,3091-3092,3094-3095 from stable branch.

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

- OpenSUSE: check if the line "include /etc/nginx/sites-enabled/*.vhost;" exists in /etc/nginx/nginx.conf before it is inserted (installation).