[RELEASE] Release of TYPO3 6.2.0alpha2

Change-Id: Ib7566d7b13a7e2c091158ea77d7f8e2077d475e0
Reviewed-on: https://review.typo3.org/22210
Reviewed-by: TYPO3 Release Team
Tested-by: TYPO3 Release Team
[TASK] Set TYPO3 version to 6.2-dev

Change-Id: Ia0b2a4cbfc50b71340e7d5133f699d62e4c46254
Reviewed-on: https://review.typo3.org/22211
Reviewed-by: TYPO3 Release Team
Tested-by: TYPO3 Release Team