stat(): throws an exception, if file does not exsist - implement file_exist() before doing a stat().

Evaluate.php, QuickFormQuery.php: 1) split exception in user/support, 2) start to implement that '!' in '{{!...' is not necessary anymore. Implemented for 'fillStoreVar' in FE Action elements.

Fixes #6866: On logout destroy STORE_USER. Session.php: check if _COOKIE['fe_typo_user'] has changed - yes: clear STORE_USER. Store.php: Rearrange functions.

F4906 Php Session Timeout: can be specified globally in configuration and per form. Affects only logged in FE User.

F4901: implement split with 'convert' (jpeg). Refactor chmod(), unlink(), rename(), rmdir(), copy() to use by QFQ version which throws an exception.

B6911 - Only fire afterInsert on new record (also fix afterUpdate, beforeInsert, beforeUpdate) - refs #6911, closes #6911

Feature #4432 - Form Submit Log, as a new FormSubmitLog QFQ-Form, with code in the manual for a FE page to browse the table.
Also added code in the manual for a MailLog FE page.

F6289: show debug button for 'All' and 'Per session'. Remove expired logfiles. Set new form variables FORM_LOG_FILE_ALL, FORM_LOG_FILE_SESSION.

F6289: First runnable version to show the formLog. Log is still empty (nothing submitted). 'per session' / 'all' not implemented.

B6168 Configuration language setting ignored: Form and FormElement editor still used uppercase config values for language configuration. Updated to the new camel case notation.

B5077 Dynamic Update & FE.type=required: Server fixed - a) dynamic calculated modeSql respected, b) formModeGlobal=requiredOff respected, c) dynamic FE with mode='hidden' are not saved anymore.

F6100 Url Forward Auto: Update Manual.rst. The F.parameter.saveAndClose has been removed again. Mode 'close' can be assigned statically or dynamic.