In TYPO3 ver. 4.x we used to include additional configuration file for overwriting some settings (ie. DB credentials) by adding the include statement
Got it! :)
The answer is: typo3conf/AdditionalConfiguration.php if this file exists it's included automatically, to overwrite some values we need to use well-known syntax ie.:
typo3conf/AdditionalConfiguration.php
From "What's new" SlideShare (page 33)