[CLEANUP] #4155 Deprecate templatehelper::getFeUserUid

Change-Id: I00e86145939d29cbe9c97e6c427cb571529c589f
Reviewed-on: http://review.typo3.org/32556
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>