With the introduction of namespaces, the references to SPL exceptions
like InvalidArgumentException were not prepended with a backslash. This
renders these references invalid (the class cannot be found in current
namespace) and leads to warnings in most IDEs.

Change-Id: I361f81ed514788852a851aebbb8677b6f533f79a
Resolves: #40536
Releases: 6.0
Reviewed-on: http://review.typo3.org/14292
Reviewed-by: Steffen Ritter
Tested-by: Steffen Ritter