New `NO_PRIOR_TEMPORAL_ACCESS` key for in situ

• vtkStreamingDemandDrivenPipeline: Adding NO_PRIOR_TEMPORAL_ACCESS()

This new key signal temporal filters that they should rely on their temporal cache and not use the CONTINUE_EXECUTING key. Calls to UpdateTimeStep(double t) are assumed to be run in sequence by the user. When used, this key should be set on the output information of the source. The new API vtkAlgorithm::SetNoPriorTemporalAccess(int) can be used to set this mode. There are 2 values this key can have: NO_PRIOR_TEMPORAL_ACCESS_CONTINUE and NO_PRIOR_TEMPORAL_ACCESS_RESET. The former value should be set when the user wants to reset and rerun the pipeline. The key gets automatically set to NO_PRIOR_TEMPORAL_ACCESS_CONTINUE after the first timestep has been run, on the user need not worry about changing the key's value on the second time step.

• vtkTemporalAlgorithm:

This template class provides mechanisms to run temporal filters. It needs to be templated over a subclass of vtkAlgorithm and to implement the pure virtual methods Initialize, Execute and Finalize.

• vtkTemporalStatistics and vtkTemporalPathLineFilter now inherit from vtkTemporalAlgorithm.