[RELEASE] Release of TYPO3 6.2.6

Change-Id: I39f6cbca69717cc894fbd9145fb1456c8ed79ef4
Reviewed-on: http://review.typo3.org/33467
Reviewed-by: TYPO3 Release Team <typo3v4@typo3.org>
Tested-by: TYPO3 Release Team <typo3v4@typo3.org>