[TASK] Release version 1.8.0

Resolves: #63128
Releases: 1.8
Change-Id: I62ac72bf8dbb9ce2841ce261dbd4ebc99bd1faf5
Reviewed-on: http://review.typo3.org/34444
Reviewed-by: Francois Suter <francois@typo3.org>
Tested-by: Francois Suter <francois@typo3.org>