FS#3897 - backup - delete unused file (interval = none), fixed mail-backup delete, moved mail-function for failed mounts/umounts

- Fixed: FS#3710 - Bug with PHP-FPM configuration since 3.0.5.4 Patch 4
- Fixed wrong function calls in system lib.

- Fixed a problem with restart of services due to the fact that Ubuntu has upstart and systemd installed, but only upstart is working without errors.

Changed: apps vhost is now a template (for apache version)
Changed: template if tags can now be of format 'version' to make version comparisons (e.g. 2.12 > 2.2 !)
Changed: New apache 2.4 syntax for deny from all (-> Require all denied) etc.

do not change parameter order in old functions

do not change parameter order in old functions

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Feature can be activated over admin mailserver settings. when activated websites uid is used instead of standard vmail-uid. this only takes effect if web and mailserver are on the same server, otherwise it will be old behaviour. switching this setting when mailboxes exist doesn't matter. Mailboxfolder will be created with website uid for this. access of postfix and dovecot now works over mysql-table mail_user. virtual_uid_maps is changed from static to mysql-table. for dovecot<->postfix communication protocoll is changed vrom lda to lmtp. disablelmtp-column is added to mail_user-table. uid and gid can be overwritten by remoting.
ONE OPEN ISSUE: since remoting has completly changed and mail_user_add function is missing at the moment, this function now was inclulded again. it is important to add the both new lines to the future function and then remove this new one.

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 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.