[RELEASE] Release of TYPO3 6.1.0

Change-Id: I1d4cb3ab9ea1f0434ece4c59eea97a0d33f23479
Reviewed-on: https://review.typo3.org/20343
Reviewed-by: TYPO3 Release Team
Tested-by: TYPO3 Release Team
[TASK] Set TYPO3 version to 6.1.1-dev

Change-Id: I6d10028d02926a264827158c124226b1dcd01e10
Reviewed-on: https://review.typo3.org/20344
Reviewed-by: TYPO3 Release Team
Tested-by: TYPO3 Release Team