add database-size monitoring. the results stored in the database may be used to add the db-size to the web-quota, too.

- Added dkim installation to installer.
- Added backup filesize in backup cronjob.

- Implemented: FS#3110 - Turn monitoring module into cron jobs

http://www.howtoforge.com/forums/showthread.php?t=62691

Revision 4063 changed the command of apt-get dist-upgrade, so it is no longer neccessary to call as it is the same one that is already executed before and we can reuse the output.

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

Note to all contributors: please use utf-8 encoding in files!

- Fixed errors in system.inc.php-

Bugfix: $app->system->unlink function had wrong parameter name, no files were deleted ever

- Added overtraffic notifications to traffic quota system (part of FS#2059 - Extend Traffic quota system)

- Added missing sys_tpl table to ispconfig3.sql and moved the definition of the table to the upd_0035.sql file as new tables cant be added in existing update files.
- added new ssl_key field to web_domain table.
- cleaned up unused code from apache plugin.

- Added new web folder named private to web folder layout. The folder is intended to store data that shall not be visible in the web directory, it is owned by the user of the web.
- Changed ownership of web root directory to root user in all security modes to prevent symlink attacks.
- Apache log files are now owned by user root.
- Improved functions in system library.