[TASK] Set TYPO3 version to 6.1.13-dev

Change-Id: If07dc024f313c5c276cb5cc5d3cfabc3fea61c68
Reviewed-on: http://review.typo3.org/33466
Reviewed-by: TYPO3 Release Team <typo3v4@typo3.org>
Tested-by: TYPO3 Release Team <typo3v4@typo3.org>