TYPO3 Core

Problem:
each PHP error/waring/notice which is handled by the errorhandling produces a log entry in the sys_log table (ext:belog) and also in the configured syslogs. This is good for debugging but might not be a wanted behaviour on production sites with old extensions installed.

Solution:
Add 2 new typo3_conf_vars for configuring which errors should be logged to each log:

$TYPO3_CONF_VARS['SYS']['syslogErrorReporting'] = E_ALL ^ E_NOTICE
Configures which PHP errors should be logged to the configured syslogs (see: [SYS][systemLog]). If set to "0" no PHP errors are logged to the syslog. Default is "E_ALL ^ E_NOTICE" (6135).

$TYPO3_CONF_VARS['SYS']['belogErrorReporting'] = E_ALL ^ E_NOTICE
Configures which PHP errors should be logged to the "syslog" table (extension: belog). If set to "0" no PHP errors are logged to the sys_log table. Default is "E_ALL ^ E_NOTICE" (6135).

Note:
Exceptions are still logged to every available log (if an exception handler is registered).
If a devlog extension is installed and $TYPO3_CONF_VARS['SYS']['enable_errorDLOG'] is enabled all error handler errors are logged to the devlog table.

(issue imported from #M12516)