[CLEANUP] Deprecate Tx_Oelib_FileFunctions.

Change-Id: I8c0c803183ec3711ab789c51851c413bbfcb0b8a
Reviewed-on: http://review.typo3.org/32476
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>