BUG: Replaced vtkInformationKeyManager with vtkFilteringInformationKeyManager and moved vector of keys to it from vtkInformationKey.  This is necessary to allow key types to be defined outside vtkFiltering.  It is also needed to deal with static initialization on the MachO (Mac OSX) runtime due to its use of lazy symbol binding.  The count and the table must be in the same translation unit, and the table must be allocated with malloc.  See comments in vtkFilteringInformationKeyManager for details.