[TASK] Verify compatibility with TYPO3 6.2

Compatibility with TYPO3 CMS 6.2 verified.
Not any real problems, mostly small cleanups.

Resolves: #58401
Releases: 1.6
Change-Id: Id785dd388b88acc68ceb7578f6b51d1d1c176b06
Reviewed-on: https://review.typo3.org/30547
Reviewed-by: Francois Suter
Tested-by: Francois Suter