[CLEANUP] #4320 Add @var type hinting to help static analysis

Change-Id: Idccf82bf20f2783c8e28f1c94c01a87e068ac8bb
Reviewed-on: http://review.typo3.org/35605
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>