[TASK] Set TYPO3 version to 6.2.9-dev

Change-Id: Ib74e8729774357fcf758ea4beb14fe45ef30aba9
Reviewed-on: http://review.typo3.org/35161
Reviewed-by: TYPO3 Release Team <typo3v4@typo3.org>
Tested-by: TYPO3 Release Team <typo3v4@typo3.org>