Ensure that folder protection is deactivated for the path of the base website when deleting a vhostsubdomain.

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

Bugfix on db-Class (datalog Update)

- Fixed missing templates and language entries
- Previous subdomain mode can be used concurrently
- Changed log path to a more convenient location

- 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.

Bugfix: Spaces need to be deleted before cron save, because they are IGNORED on validation but lead to a non-functional cron.
Storing minute / hour / etc. values like "1, 23, 26" (with spaces) is allowed in validation and interface but leads to a BLOCKED crontab file and to non-functional crons of the whole web user.

This option can be enabled under System > Server config and is named "Web folder protection".

Implemented: FS#560 - Add support for APS (Application Packaging Standard)

Improved: FS#2131 - skip network reconfigure requests on mirror servers that are for a different server_id

Implemented: FS#2131 - skip network reconfigure requests on mirror servers that are for a different server_id

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

- Fastcgi: delete .php-fcgi-starter directory if another PHP mode is used.