[BUGFIX] flock() calls in TYPO3 prevent NFS hosting

flock() happens in several places in TYPO3. This function does
not work properly on NFS shares. t3lib_lock should be used
instead.

Change-Id: I30392bf06c5e20e27e929fb06d77ee9f96978902
Resolves: #31460
Releases: 4.7, 4.6, 4.5
Reviewed-on: http://review.typo3.org/6778
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind
Reviewed-by: Tolleiv Nietsch
Tested-by: Tolleiv Nietsch
Reviewed-by: Xavier Perseguers
Reviewed-by: Steffen Gebert
Tested-by: Steffen Gebert